XenDesktop

The new Citrix XenDesktop release targets laptop security with new virtualization software

2010-08-25T21:02:04Z

Citrix Systems today announced a new release of Citrix® XenDesktop™ that extends the benefits of desktop virtualization to millions of enterprise laptop users with the addition of two new technologies: Citrix XenClient™ and Citrix XenVault™. Together, these two technologies make it easy for IT to incorporate mobile laptop users into a unified enterprise desktop virtualization strategy with unparalleled security and simplicity – including corporate-owned laptops managed by IT, as well as user-owned devices brought in by contractors or employees in a BYOC (bring your own computer) program.

Desktop virtualization is rapidly growing in popularity as a more secure, flexible way to deliver Windows desktops to business users in any location. With this new release, companies of all sizes can now deploy a single desktop virtualization solution that seamlessly supports both desk-based and laptop users in just about any scenario. With laptop users representing half of the workforce in many companies, today’s announcement represents a major milestone that significantly expands the reach of desktop virtualization to millions of new users.

Most mobile employees today do the majority of their work on company-owned laptops. For these workers, the best solution is a virtual desktop that runs directly on their laptop. This approach gives IT all the central management and security benefits of server hosted virtual desktops (VDI), combined with all the flexibility and ability to be disconnected from the network that come with traditional, locally installed desktops. And because the desktops runs in a local VM at all times, users never have to go through the cumbersome time consuming process “checking-out” their virtual desktop by downloading it from a central server each time they leave the office. These new capabilities are all enabled by the new XenClient technology, a groundbreaking client-side hypervisor developed in close collaboration with Intel, and optimized for the Intel® Core™ vPro™ technology.

In many companies, there is also a growing trend toward user-owned laptops that are not controlled by IT. This trend frequently involves contractors who bring their own device to a project, as well as employees who bring their own laptop to work as part of a BYOC program. In these scenarios, users do not want IT installing software on their personal laptops, nor does IT want to take on the cost and hassle of managing personal devices. IT’s primary goal in these scenarios is to ensure these workers are productive, and that any corporate data on their personal laptops is secure at all times. For user-owned devices, the simplest solution is to deliver the corporate applications these users need as an on-demand service, while ensuring that any data created by those corporate apps is automatically encrypted. This capability is enabled through the new XenVault technology.

With the addition of the new XenClient and XenVault features, XenDesktop extends its lead as the most comprehensive and flexible desktop virtualization solution on the market.

Key Facts and Highlights (XenClient):

Enables Virtual Desktops “To Go” – XenClient is a client-side hypervisor that enables virtual desktops to run directly on client devices. It provides all the security and central management of VDI, while allowing users to seamlessly work online or disconnected without any cumbersome check-in or check-out requirements, just as they would with a traditional locally installed desktop. While XenClient can be run on any supported PC hardware, it is ideally suited to corporate-owned laptops.
Control for IT, Flexibility for Users – XenClient makes it easy for IT to deliver a secure, centrally managed corporate desktop environment to laptop users without compromising user experience. They can even set up a second personal virtual desktop on the same laptop, giving users full freedom, without compromising corporate security.
Centralized Backup and Recovery – When disconnected from the network, XenClient operates just like a traditional installed desktop. As soon as users connect to the network, it automatically synchronizes any changes with the datacenter, ensuring full centralized backup of all corporate laptops. If a laptop is ever lost or stolen, users can easily restore their full desktop environment exactly like it was to a new laptop, while data on the original laptop can be wiped remotely.
Portable and Persistent Desktop Images – By separating the operating system from the underlying hardware, desktop images can now be created, secured, deployed and moved across any supported hardware, greatly reducing the maintenance burden on IT and simplifying disaster recovery for laptop users.
Expanded Hardware and Device Support – XenClient now also includes several new capabilities that were not supported in the initial beta release. These include multiple usability and security enhancements, new synchronization features, and expanded support for hardware platforms, wireless adapters and USB-based devices such as webcams, iPads, iPhones, Androids, BlackBerrys and Windows Mobile devices.
Optimized for Intel® vPro™ – The XenClient hypervisor was designed jointly with Intel to work seamlessly with the underlying hardware. Intel Core vPro processors are designed to provide the best experience for end-users and IT through use of Intel hardware-assisted virtualization, management and security technologies.

Key Facts and Highlights (XenVault):

Protects and Isolates User Data – The new XenVault technology automatically and transparently saves any user data created by corporate apps into an encrypted folder, ensuring that it is protected at all times from unauthorized users.
Ideal for Contractors and BYOC – Because XenVault supports both virtual and physical desktops, it is an ideal solution for contractors and employee-owned laptops where users don’t want IT installing software on their personal laptops. When a contract is over, an employee terminates, or the laptop is lost or stolen, corporate data remains secure, and can even be wiped remotely.
Supports XenApp and App-V – XenVault automatically encrypts data created by any corporate app that is delivered by Citrix XenApp™ (or the XenApp feature of XenDesktop) or Microsoft App-V.

Supporting Quotes:
Gordon Payne, Senior Vice President and General Manager, Desktop Division, Citrix
“This new release of XenDesktop represents an important next step to realizing the benefits that desktop virtualization can deliver across all users in the enterprise, including the growing number of mobile workers using laptops as their primary device. The new XenClient and XenVault technologies extend IT’s ability to manage each desktop component separately, making desktop management far more secure, scalable and cost effective.”

Rick Echevarria, Vice President, Intel Architecture Group
and General Manager, Business Client Platform Division
“As desktop virtualization continues to grow as an option for investing IT resources in strategic projects, rather than supporting desk-side maintenance visits, Citrix and Intel teamed on an innovative solution that unites the benefits of XenClient and Intel Core vPro processors. Our collaboration has produced an intelligent approach to desktop virtualization that delivers uncompromised performance, security and manageability to workers and IT.”

Al Gillen, Program Vice President, System Software, IDC
“For desktop virtualization to be adopted in a mainstream way across the entire enterprise, mobile users are a critical use case that has so far not been fully addressed. Technologies like Citrix XenClient that can deliver the control, security and centralized management for IT while providing the personalization and flexibility that users want, should help propel desktop virtualization into a strategic initiative in enterprises large and small.”

Michael Barnas, Director, Application Services, Sonnenschein Nath & Rosenthal LLP
“Our attorneys work extremely long hours and pride themselves on delivering the highest levels of client responsiveness. Providing a single laptop where users have secure access to all their corporate applications and also to their personal environment really helps with work-life balance. We see XenClient being a significant addition to our desktop virtualization strategy as we feel this can fulfill a critical need for our attorneys, while allowing us to continue to maintain the highest levels of security and control.”

Steve Lalla, Vice president and General Manager, Client Product Group, Dell
“We see tremendous benefits to our customers from the security and flexibility that XenClient brings to both IT and end users. By integrating their client hypervisor, XenClient, with their desktop virtualization architecture, XenDesktop, Citrix takes a major step forward in giving enterprises the ability to deliver centrally managed virtual desktops to all users. And by enabling support for selected Latitude laptops and OptiPlex desktops, Dell is creating the foundation for future enterprise-class deployments of this emerging client virtualization technology.”

Pricing and Availability:

The new XenClient and XenVault technologies will both ship in the new XenDesktop 4, Feature Pack 2 release, available at the end of September.
XenClient is available at no additional charge for XenDesktop Enterprise and Platinum editions customers with current Subscription Advantage agreements.
XenVault is enabled through a plug-in to the Citrix Receiver™ software client, which is available at no additional charge to all XenDesktop and XenApp customers.
Citrix XenDesktop, including the new XenClient and XenVault technologies, will be demonstrated in the Citrix booth #1219 at VMworld San Francisco, Aug. 30 – Sept. 2.

Scalability of Citrix XenDesktop 4 on Microsoft Windows Server 2008 R2 Hyper-V Whitepaper

2010-08-20T07:57:36Z

Citrix partners and customers alike are looking to build scalable XenDesktop environments on Microsoft Windows Server 2008 R2 Hyper-V and have requested guidance around what to expect when scaling up those environments. The Citrix team, with help from HP and Microsoft, collaborated on creating a large-scale virtual desktop environment at HP’s Houston Solution Center. This document provides the information gathered during that seven-week project.
The virtualization environment was entirely Microsoft Windows Server 2008 R2 Hyper-V. The desktop hosting infrastructure consisted of 3500 desktop virtual machines each receiving a streamed Windows 7 image from Citrix Provisioning Server. The server virtualization infrastructure consisted of 15 virtual machines that hosted the support services for delivering and testing the desktops.
Login VSI 2.1 from Login Consultants was used to simulate the workload inside the virtual desktops. The Login VSI medium level workload consists of Microsoft Office 2007, Microsoft Internet Explorer, and Adobe tasks executed in a repeating 12-minute loop. The Login VSI script recorded response times so the user experience could be quantified for comparison.

Click here to download and view the Whitepaper

How to Configure Dazzle for Use with XenDesktop and Provisioning Services

2010-08-17T12:53:16Z

In XenDesktop, a single image desktop is assembled dynamically from a Provisioning Services vDisk in Standard Image mode each time the user logs on. When the user logs off, any changes made to the desktop during the session are discarded. This means that if a user of a single image desktop subscribes to applications using Dazzle, these subscribed applications are not present on the desktop the next time the user logs on. To enable single image desktop users to subscribe to applications using Dazzle, you must configure your XenDesktop environment so that subscribed applications are preserved.

Note: The configuration changes detailed below are only required for desktops generated from vDisks in Standard Image mode. If you are using vDisks in Private Image mode, where each desktop uses a separate vDisk, users’ subscribed applications are saved to the vDisk along with any other changes they make.

Streaming Package Management

If you are using offline applications with XenDesktop, there are various settings that can be configured to improve performance.

Treating Offline Applications as Online

When a user subscribes to an application that is published on XenApp with the Streamed to client setting and configured for offline access, Dazzle downloads the streaming package to the user device. With XenDesktop single image desktops, this approach is undesirable because the (typically large) streamed package is discarded when the user logs off.

When using Dazzle exclusively in a XenDesktop environment, there is no need to configure offline applications for offline access. If you publish offline applications as Streamed to client, but do not configure them for offline access, the user device downloads, on demand, just those parts of the streaming package that are required for the application to run.

Alternatively, if you want to publish offline applications that can be used on both virtual and local desktops, Dazzle can be configured to prevent the entire streaming package being downloaded for applications configured for offline access. To do this, you must set the following registry key on the master target device before you image the vDisk.

Caution! This procedure requires you to edit the registry. Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Back up the registry before you edit it.

On the master target device, navigate in the system registry to:
HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\Dazzle on 32-bit operating systems
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\Dazzle on 64-bit operating systems

Under the Dazzle node, add a REG_SZ value named TreatOfflineAppsAsOnline and set the value to true.
Note: This setting does not affect offline applications that are not enabled for offline access.

Adding Common Streaming Packages to the vDisk

To decrease start times for offline applications and to minimize the infrastructure load caused by users downloading streaming packages, Citrix recommends that you add streaming packages for common applications to the master target device before you image the vDisk.

When deciding which streaming packages to add to the vDisk, consider factors such as the size of the packages and frequency with which they are updated, plus the number of users likely to be running the applications.

On the master target device, navigate in the system registry to:
HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\Rade on 32-bit operating systems
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\Rade on 64-bit operating systems

Under the Rade node, add a REG_SZ value named RadeRunSwitches and set the value to –e.

Use Dazzle to subscribe to the applications that you want to add to the vDisk.

Start each offline application to populate the cache, which is typically located at C:\Program Files (x86)\Citrix\RadeCache.

Navigate in the system registry to:
HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\Rade on 32-bit operating systems
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\Rade on 64-bit operating systems

Under the Rade node, delete the RadeRunSwitches value.

Check that the \Deploy folder (typically located at C:\Program Files (x86)\Citrix\Deploy) is empty. If necessary, use the RadeDeploy utility to remove applications by navigating to the \Streaming Client folder from a command prompt and typing radedeploy /delete:<ApplicationName>.

Dazzle Configuration

Users can add new stores if you enable this option when you deploy Dazzle. However, for the optimum user experience, Citrix recommends that you preconfigure at least one store.

Using Merchandising Server

Citrix recommends deploying Dazzle using Merchandising Server as this allows desktops to be updated automatically. For more information about deploying Dazzle with Merchandising Server, see the Dazzle documentation.

Merchandising Server dynamically provides Dazzle configuration data to the desktop when a user logs on, which provides maximum flexibility. However, to prevent unnecessary updates, Citrix recommends that you configure Citrix Receiver not to update the plug-ins on single image desktops. For more information about disabling plug-in updates in Citrix Receiver, see the Citrix Receiver documentation.

Configuring Dazzle Using Group Policy and the Registry

If Merchandising Server is not available in your environment, specify a default store when you install Dazzle on the master target device. All users of single image desktops that use this vDisk will be able to access this store. For more information about deploying Dazzle manually, see the Dazzle documentation.

Once Dazzle is installed, you can add additional stores for single image desktop users by using Group Policy to set registry-based policies on the desktops. Dazzle store details are held in the registry under the HKEY_CURRENT_USER\Software\Citrix\Sites node. For more information about Group Policy, see http://technet.microsoft.com/en-us/windowsserver/bb310732.aspx.

For more information please refer to CTX124932

Citrix XenDesktop Setup Wizard on Microsoft Hyper-V video demo

2010-08-14T07:43:22Z

This demo from Citrix shows how you can deploy virtual desktops with Citrix XenDesktop Setup Wizard on Microsoft Hyper-V.

Citrix XenDesktop User Bandwidth Planning Guide

2010-08-09T09:16:20Z

Citrix Consulting Solutions has released a white paper that gives an overview of bandwidth planning and requirements for XenDesktop.

Overview
Regardless of the flavor of virtual desktop being implemented (hosted shared, hosted VM-based VDI, local streamed, etc.), the network plays a critical role, especially for remote and branch office
users. If the network bandwidth is not planned properly, users will most likely experience poor performance with their virtual desktop.
When planning a virtual desktop solution, one must think about how the user’s workload will evolve. The design must be able to support future activities, not just today’s. As can be observed,
the content users interact with is changing from textual-based to more multimedia-based. Any solution and methodology must be able to account for these changes in user behavior. Although
there is no single answer to the question of how much bandwidth will a user need, this planning guide provides recommendations on how to estimate the user network requirements.

Click here to download the whitepaper XD - Planning Guide - User Bandwidth Requirements

Citrix XenDesktop 4 Service Pack 1 Overview

2010-08-05T08:33:53Z

This video provides an overview of Service Pack 1 for XenDesktop 4.

HP Converged Infrastructure enterprise reference architecture for client virtualization: Citrix XenDesktop on Microsoft Windows Server 2008 R2 Hyper-V

2010-08-04T10:51:46Z

HP, Citrix, and Microsoft® collaborate at an engineering level to ensure that you can benefit from software, hardware, and service solutions that are jointly tested, certified, and tuned to deliver optimal server performance. Engineering teams have developed a range of recommended configurations and services for Citrix applications, focusing on particular business needs and technical scenarios. Figure 1 depicts the range of HP reference architectures for virtual desktop infrastructure (VDI).

Available today, HP Converged Infrastructure provides a blueprint for the data center of the future, eliminating costly, rigid IT silos so you can spend much more of your IT budget on business innovation. This infrastructure converges servers, storage, and networks with facilities – all managed through a common management platform. The result is a new level of simplicity, integration, and automation that can accelerate business outcomes that matter most.
This white paper describes an HP Converged Infrastructure enterprise reference architecture for client virtualization featuring Citrix XenDesktop on Microsoft Windows® Server 2008 R2 Hyper-V. Based on HP ProLiant BL460c G6 server blades and HP StorageWorks P4800 G2 SAS BladeSystem iSCSI SAN storage, this reference architecture delivers an enterprise virtual desktop solution capable of supporting approximately 800 Microsoft Office 2007 users on Microsoft Windows XP.

Click here to download and read the Whitepaper

Citrix releases XenDesktop 4 Service Pack 1

2010-07-30T06:42:23Z

With the Service Pack 1 for XenDesktop 4, Citrix has added Delegated Administration and Configuration Logging Components to it's XenDesktop 4 version.

In addition to the Virtual Desktop Agent (VDA) enhancements found here, which are recommended for all XenDesktop implementations, Citrix XenDesktop 4 Service Pack 1 also provides optional components that are intended for large, enterprise deployments. From the links on this Technote page, you can download components that add Delegated Administration and Configuration Logging for XenDesktop 4. These features enable large IT organizations to divide tasks and permissions by role, and report on all changes made to the configuration of the solution.

Click here to download Citrix XenDesktop 4 Service Pack 1

Citrix releases Best Practices Guide for Upgrading Citrix XenDesktop 4 Virtual Desktop Agent

2010-07-25T18:45:47Z

Citrix recently released updates for the Citrix XenDesktop 4.0 Virtual Desktop Agent designed to improve the end user virtual desktop experience. Service Pack 1 which includes Hotfixes 1, 2, and 3 for the Citrix XenDesktop 4 Virtual Desktop Agent was released in July 2010. As administrators prepare to upgrade their existing environment with the most recent Virtual Desktop Agent (VDA), there are different implementation considerations for different types of virtual desktop deployments. This paper addresses upgrading the VDA on virtual desktops in two distinct categories:

Pooled Desktops, also known as hosted VM-based desktops, are defined as a group of virtual desktops that utilize a single virtual desktop image delivered by the Provisioning Services feature of XenDesktop. Guidance for updating the VDA in this environment is provided in the Pooled Desktops section.
Assigned Desktops are defined as a group of virtual desktops that utilize a dedicated virtual machine for each desktop. Assigned desktops do not utilize Provisioning Services. Guidance for updating the VDA in this environment is provided in the Assigned Desktops section.

Click here to download the Best Practices for Upgrading Citrix XenDesktop 4 Virtual Desktop Agent

Emergence of Virtual Desktop Solutions - HP joins Microsoft and Citrix to get it started

2010-06-25T08:16:02Z

About 4 years ago when Citrix started investigating the virtual desktops technology, there were some brave souls who were assembling the piece parts themselves to try to make something happen. A lot has happened since then - there are now viable options that customers have used to obtain large scale virtual desktop implementations.

So, what's next? Solutions...

In order for a technology and product sets to go mainstream faster, customers need the products to be turned into solutions. This is true especially for something like desktop virtualization, which has inherent complexity due to multiple moving parts and challenges the norms of traditional desktop computing. In my assessment, for every customer who prefers to pick the best of breed products and integrate it for their own infrastructure; there are 10 (yes, I made it up - but pick you double digit number here) that prefer integrated solutions with ideally plug-n-play experience.

We are not quite there in terms of the availability of plug-n-play solutions; however, we have now entered the phase where the customers will drive the creation of these solutions - with a goal of having a simpler experience in adopting and scaling virtual desktops. And, all these solutions will continue to drive desktop virtualization to mainstream reality.

HP joins Citrix & Microsoft to offer 2 solutions and a reference architecture

Earlier this week, HP joined Citrix-Microsoft and added their own special sauce to offer customers solutions to get started with virtual desktops. Customers who are looking for easy path to virtual desktops can now leverage two offers from HP - VDI Ignite and VDI Activate.

VDI Ignite: Get your virtual desktop strategy and pilot for as little as $10K

VDI Ignite combines the Citrix and Microsoft Kick Start offer (250 seats for only $28 per user) with HP's Client Transformation Workshop for only $10,000. Customers can get their strategic vision defined for transforming their desktop computing environment in addition to getting the software infrastructure for the first 250 users. It is a great solution for customers who are looking to define their strategy and are unsure about when and how to start.

VDI Activate: Get your virtual desktop strategy provides along with a 250 user implementation for only $26K

For only $26000, customers can not just determine the right virtual desktop strategy, but also get 250 users up and running with HP client services. VDI Activate includes the VDI Ignite offer, the 250 licenses and HP's Client Transformation Workshop, plus it adds implementation services from HP to rapidly bring a virtual desktop solution to life in a customer's environment. This is a perfect solution for customers who are ready to start and can now get their first 250 users implemented as a pre-packaged solution.

Click here to read the full Citrix blog post

How To: Test that HDX MediaStream for Flash is working on your Client

2010-06-24T11:25:25Z

How To video on how to Test that HDX MediaStream for Flash is working on your Client.

Citrix XenDesktop Recognized as Best of Tech-Ed Winner

2010-06-21T17:14:25Z

Citrix Systems, Inc. today announced that Citrix XenDesktop 4 was named winner of the Breakthrough Product in the Best of Tech-Ed 2010 awards program by Penton Media's Windows IT Pro and SQL Server Magazine. The Breakthrough Product award is the top honor given by the editors for the most innovative product in all Best of Tech-Ed 2010 award categories. According to the editors, Citrix XenDesktop 4 was chosen because, "Citrix is providing easy and powerful virtual desktops, and there's a good chance that will be the future of IT."

Best of Tech-Ed 2010 awards recognize companies that offer innovative products for the industry. The judges reviewed 298 products and services submitted for the contest and chose 46 finalists to be interviewed at the Microsoft Tech-Ed North America 2010 IT pro conference in New Orleans, Louisiana on June 9th. Winners were then chosen based on their innovation, strategic importance to the market, competitive advantage and exceptional value to customers, and announced later that evening in an invitation-only reception.

"Choosing the best product in each of 14 categories -- from our list of 46 products -- was both daunting and exhilarating for our judging panel," said Jason Bovberg, Senior Editor of Windows IT Pro. "All 46 finalists represent highly distinguished products and services in their categories. Through our exhaustive interview process, it was clear that some of our winners stood a step above the pack, whereas other picks were more difficult to determine. The winners in those categories typically offered an edge in product functionality, boasted enhanced feature sets in new versions, or introduced innovative technology -- giving them a slight advantage over the competition."

XenDesktop 4 is a comprehensive desktop virtualization solution that delivers a complete Windows desktop experience as an on-demand service to any user, anywhere, making virtual desktops a mainstream reality for hundreds of millions of corporate employees for the first time ever. Unlike first-generation VDI-only solutions that were applicable only to a narrow set of users, XenDesktop 4 with its new FlexCast(TM) delivery technology is the first product in the industry to support every major desktop virtualization model in a single, integrated solution -- a breakthrough that improves ROI, simplifies management and extends the benefits of virtualization to every employee in the enterprise.

"XenDesktop's recognition as winner of the Breakthrough Product in the Best of Tech-Ed award program is very exciting for us. XenDesktop is the only desktop virtualization solution to win this prestigious award," said Raj Dhingra, group vice president and general manager, XenDesktop product group at Citrix Systems. "We have been very focused on adding innovative capabilities to XenDesktop to drive mainstream adoption of virtual desktops. Awards like Best of Tech-Ed validate our vision for delivering a market-leading, comprehensive desktop virtualization solution that meets the broad range of customer needs in this thriving sector of the industry."

A complete list of the Best of Tech-Ed 2010 award winners is available at http://www.windowsitpro.com and http://northamerica.msteched.com .

Citrix XenDesktop vs. VMware View 4: Multiple User Performance tests

2010-06-08T19:24:51Z

This video shows the user experience of XenDesktop and View when running 6 simultaneous sessions on a simulated T1. The workloads were generated using Login Consultants "Login VSI" tool. WAN emulation provided by an Apposite device.

How to run the Citrix HDX Monitor for XenDesktop

2010-06-07T19:49:29Z

The HDX Monitor is a tool to validate the operation of XenDesktop's HDX stack including the latest HDX MediaStream for Flash and HDX RealTime features. Install this tool on your virtual desktop to obtain helpful technical details about your HDX experience. The tool is organized into sections that cover the various HDX technologies. Use it to view bandwidth usage, session settings and performance metrics.

Download the HDX Monitor tool from the Link below
http://hdx.citrix.com/hdx-monitor/downloads

Install the Tool on your Virtual Machine which is Launched from the XenDesktop.

Once the Installation is complete Run the HDX Monitor Tool on the Virtual Machine Lauched from the XenDesktop.

Click here to read the full blog post from Citrix.com

Citrix updates the VDA Agent for XenDesktop

2010-06-01T11:33:27Z

A new version of the Virtual Desktop Agent(VDA) from Citrix was released yesterday, and you should review the long list of Fixes that are incorperated in this update! It's updated both for x32 bit os versions and x64.

Here is a quick overview of what's fixed in this release:

When an application running inside a virtual desktop changes the state of the Caps Lock, Num Lock, or Scroll Lock keys programmatically, the LED indicators on the endpoint keyboard are not updated to indicate the changed state to the user. As a result, users can be locked out of external Web sites if they inadvertently mistype and submit their case-sensitive passwords multiple times.
Using workspace control to log off a session on a Virtual Desktop Agent running on Windows XP when the session desktop is locked can cause the session to stop responding.
Print jobs on network print servers are deleted unexpectedly when an administrator logs off from a session.
When using a Windows 7 or Windows Vista Virtual Desktop Agent with a custom logon message, the session becomes unresponsive if you do not click OK in the the message dialog box within a few minutes.
A system exception can cause the Citrix Audio Service to stop.
When connecting to a virtual desktop session with a new user profile for the first time, both the endpoint cursor and the virtual desktop cursor are visible in the session.
Windows Media content embedded in a Web page does not invoke HDX MediaStream Multimedia Acceleration on Virtual Desktop Agents running on Windows 7.
Attempts to reconnect to a disconnected virtual desktop session can fail with EventID 1008.
HDX Mediastream Multimedia Acceleration does not work properly with some media players, including GOM Player. For the fix to work, [Use WM ASF Reader] or [Use Windows Media Source] options may need to be selected in GOMPlayer preferences.
Single sign-on to a XenDesktop session can intermittently fail, causing users to be prompted for credentials when launching a virtual desktop. This can result in failures to reconnect and unexpected behavior of PicaSvc.exe until the Citrix ICA Service is restarted.
Attempts to connect to a virtual desktop session might fail intermittently.
Attempts to reconnect to a disconnected session might fail. When this happens, the virtual desktop appears locked and users cannot pass Ctrl+Alt+Delete to invoke the Windows logon screen; a 9032 ThinWire error is logged in the Event Log of the Virtual Desktop Agent.
This fix addresses logon issues, including excessive logon times and reconnect failures.
Unresponsive windows in a virtual desktop session can prevent users from reconnecting to a disconnected session.
When resizing the Desktop Viewer window, the Windows taskbar shifts up and down three times, and six times when maximizing the window. The issue does not occur on systems with Fix #230577 installed. After applying this fix, resizing the window causes the taskbar to move up and down only once, and twice when maximizing the window.
Attempts to reconnect to a session from a different endpoint device using a different type of smart card reader than the original session fail and the login becomes unresponsive.
After making an RDP connection to a Virtual Desktop Agent, ICA connection attempts no longer succeed.
Intermittent failures to reconnect to a Virtual Desktop Agent might be observed. The virtual desktop appears blacked out and is unresponsive at the console.

To learn more and download check out the following 2 links:

Hotfix XDE400VDAWX64003 (Version 4.0.4546) - For Citrix XenDesktop 4.0 Virtual Desktop Agent x64

Hotfix XDE400VDAWX86003 (Version 4.0.4546) - For Citrix XenDesktop 4.0 Virtual Desktop Agent x86