http://social.technet.microsoft.com/wiki/contents/articles/1349.hyper-v-2008-r2-update-list.aspx
Note: This article is based on Hyper-V 2.0, this updates listed do not apply to Hyper-V 3.0 (Server 2012)
The latest Hyper-V service packs, updates, and hotfixes for Windows Server 2008 R2 are listed here in chronological order.Last Updated: April 10, 2013
You can subscribe to updates for this page using RSS: http://social.technet.microsoft.com/wiki/contents/articles/hyper-v-update-list-for-windows-server-2008-r2/rss.aspx
Updates that are available on Windows Update are indicated, as well as the download location for those that are available at the Microsoft Download Center. These updates and hotfixes can help avoid some known issues and may save you a support call. 
Note: Some updates are required only under certain circumstances, as noted in the table. Additional pages have been created for Hyper-V in Windows Server 2008 
(which includes updates for Windows Server 2008 Service Pack 2) and forHyper-V in Windows Server 2012. A hotfix is intended to correct only the problem that is described in the article. You should not apply the hotfix if you have net seen the symptoms.
Applies To: Windows Server 2008 R2
(This wiki page is part of a pilot program to remove topics such as this one from the TechNet and MSDN libraries and move them to the wiki. Why not leave this on the Library? Customers asked for an RSS feed so that they can get a notification when the list is updated and a new update is released. The RSS feed for this wiki article ishttp://social.technet.microsoft.com/wiki/contents/articles/hyper-v-update-list-for-windows-server-2008-r2/rss.aspx.)
The following table shows the list of software updates and hotfixes for Hyper-V in Windows Server 2008 R2. Updates that are available on Windows Update are indicated, as well as the download location for those that are available at the Microsoft Download Center. These updates and hotfixes can help avoid some known issues and may save you a support call.
Note Some updates are required only under certain circumstances, as noted in the table. Also, you may want to see thelist of updates for Hyper-V in Windows Server 2008 (which includes updates for Windows Server 2008 Service Pack 2)(http://go.microsoft.com/fwlink/?LinkId=183322). A hotfix is intended to correct only the problem that is described in the article. You should not apply the hotfix if you have net seen the symptoms.
In some cases, the version number of the Integration Services (also known as Integration Components) has changed. The IC version number for the RTM version of Windows Server 2008 is 6.0.6001.17101.
The IC version number for Windows Server 2008 R2 is 6.1.7600.16385.
The IC version number for Windows Server 2008 R2 SP1 is 6.1.7601.17514.
Other IC version numbers related to KBs are listed with the KB in the table below for your reference.
If you are looking just for the recent updates, see List of Hyper-V Packages Updated After the Release of Windows Server 2008 R2 Service Pack 1 (SP1).
Comprehensive list of Hyper-V R2 updates
| KB Article and Date Published | Required? | IC Version | Applies to: | Availability | |
| KB974598: “You receive a "Stop 0x0000007E" error on the first restart after you enable Hyper-V on a Windows Server 2008 R2-based computer” (http://support.microsoft.com/kb/974598 )Published on 10/1/2009 | Yes, if you encounter this error and your server uses a “C-state” (lower power state) that is supported by the processor, but is not supported by Hyper-V. | N/A | Windows Server 2008 R2 | Hotfix | |
| KB974909: "The network connection of a running Hyper-V virtual machine is lost under heavy outgoing network traffic on a Windows Server 2008 R2-based computer" (http://support.microsoft.com/kb/974909 )Published on 10/21/2009 | Yes | N/A | Windows Server 2008 R2 | Hotfix | |
| KB975354: “A Hyper-V update rollup package is available for a computer that is running Windows Server 2008 R2” (http://support.microsoft.com/kb/975354 )Published on 10/21/2009 | Yes, if you are running a backup or restore solution. | 6.1.7600.20542 | Windows Server 2008 R2 | Hotfix | |
| KB975530: “Stop error message on an Intel Xeon 5500 series processor-based computer that is running Windows Server 2008 R2 and that has the Hyper-V role installed: "0x00000101 - CLOCK_WATCHDOG_TIMEOUT" (http://support.microsoft.com/kb/975530 )Published on 11/20/2009 | Yes, if you are running Hyper-V on the affected hardware. | N/A | Windows Server 2008 R2 | Download Center, Hotfix | |
| KB974672: “Virtual machines stop responding (hang) during startup and the Vmms.exe process crashes on a Windows Server 2008 R2 computer that has the Hyper-V role installed“ (http://support.microsoft.com/kb/974672 )Published on 10/14/2009 | No | N/A | Windows Server 2008 R2 | Hotfix | |
| KB977894: “MS10-010: Vulnerability in Windows Server 2008 Hyper-V could allow denial of service” (http://support.microsoft.com/kb/977894 )Published on 2/9/2010 | Yes | N/A | Windows Server 2008, Windows Server 2008 SP2, Windows Server 2008 R2 | Security Bulletin | |
| KB980856: “Stop error in Windows Server 2008 R2: "0x000000CA PNP_DETECTED_FATAL_ERROR"” (http://support.microsoft.com/kb/980856 )Published on 3/12/2010 | Yes, if you store VHDs on non-PNP disks. | N/A | Windows Server 2008 R2 | Hotfix | |
| KB981618: “The computer stops responding or restarts during the Hyper-V Live Migration process in Windows Server 2008 R2” (relates to AMD Errata 383) (http://support.microsoft.com/kb/981618 )Published on 3/27/2010 | Yes, if you are running Hyper-V on AMD processors. | N/A | Windows Server 2008 R2 | Hotfix | |
| KB981836: “Network connectivity for a Windows Server 2003-based Hyper-V virtual machine is lost temporarily in Windows Server 2008 R2” (http://support.microsoft.com/kb/981836 )Published on 4/28/2010 | Yes, if the server running Hyper-V has a virtual machine that is running Windows Server 2003. | 6.1.7600.20683 | Windows Server 2008 R2 | Hotfix | |
| KB981791: “"STOP: 0x0000001a" error message on a computer that has an Intel Westmere processor together with the Hyper-V role installed on Windows Server 2008 or on Windows Server 2008 R2” (http://support.microsoft.com/kb/981791 )Published on 5/5/2010 | Yes, if you are running Hyper-V on Intel Westmere processors. | N/A | Windows Server 2008 R2 | Hotfix | |
| KB2133637: “The computer stops responding at startup in Windows Server 2008 R2 if you enable the Hyper-V role and if you have more than 512 GB of RAM” (http://support.microsoft.com/kb/2133637 Published on 6/17/2010 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 | Hotfix | |
| KB2230887: “Hotfix: Hyper-V Dynamic Memory does not work on a Windows Server 2008 Standard Edition or Windows Web Server 2008 virtual machine (VM)” (http://support.microsoft.com/kb/2230887 Published on 7/5/2010 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 | Hotfix | |
| KB2223005: “The network connection is lost on a Hyper-V virtual machine” (http://support.microsoft.com/kb/2223005 )Published on 8/12/2010 | Yes, if the server running Hyper-V has a virtual machine that is running Windows Server 2003. | 6.1.7600.20778 | Windows Server 2008 R2 | Hotfix | |
| KB2264080: “An update rollup package for the Hyper-V role in Windows Server 2008 R2: August 24, 2010” (http://support.microsoft.com/kb/2264080 )Published on 8/24/2010 | Yes | N/A | Windows Server 2008 R2 | Hotfix | |
| KB982210: "Startup time increases or hangs at the logon “Welcome” screen if you frequently backup Hyper-V virtual machines on a Windows Server 2008 R2 system." (http://support.microsoft.com/kb/982210 )Published on 11/24/2010 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 | Hotfix | |
| KB2345316: "MS10-102: Vulnerability in Hyper-V could allow denial of service" (http://support.microsoft.com/kb/2345316 )Published on 12/14/2010 | Yes | N/A | Windows Server 2008 R2 | Security Bulletin | |
| KB2496089: "The Hyper-V Virtual Machine Management service stops responding intermittently when the service is stopped in Windows Server 2008 R2" (http://support.microsoft.com/kb/2496089 )Published on 2/23/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 | Hotfix | |
| KB2485986: "An update is available for Hyper-V Best Practices Analyzer for Windows Server 2008 R2" (http://support.microsoft.com/kb/2485986 )Published on 2/24/2011 | Yes | N/A | Windows Server 2008 R2 | Hotfix | |
| KB976932: "Information about Service Pack 1 for Windows 7 and for Windows Server 2008 R2" (http://support.microsoft.com/kb/976932 )Published on 3/15/2011 | Yes | 6.1.7601.17514 | Windows Server 2008 R2 | Download Center | |
| KB2519946: “Timeout Detection and Recovery (TDR) randomly occurs in a virtual machine that uses the RemoteFX feature in Windows Server 2008 R2” (http://support.microsoft.com/kb/2519946 Published on 3/23/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| KB2263829: "The network connection of a running Hyper-V virtual machine may be lost under heavy outgoing network traffic on a computer that is running Windows Server 2008 R2 SP1" (http://support.microsoft.com/kb/2263829 ) Published on 4/5/2011 | Yes | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| KB2517374: "You cannot start virtual machines on a computer that is running Windows Server 2008 R2 and on which a CPU is installed that supports the AVX feature" (http://support.microsoft.com/kb/2517374 )Published on 4/5/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2523676: “GPU is not accessed leads to some VMs that use the RemoteFX feature to not start in Windows Server 2008 R2 SP1” (http://support.microsoft.com/kb/2523676 Published on 4/19/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| KB2534356: “Some CPU cores are parked while other active CPU cores have a heavy workload in Windows Server 2008 R2” (http://support.microsoft.com/kb/2534356 Published on 4/26/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2521348: "A virtual machine online backup fails in Windows Server 2008 R2 when the SAN policy is set to "Offline All"" (http://support.microsoft.com/kb/2521348 ) Published on 4/27/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2494016: "Stop error 0x0000007a occurs on a virtual machine that is running on a Windows Server 2008 R2-based failover cluster with a cluster shared volume, and the state of the CSV is switched to redirected access" (http://support.microsoft.com/kb/2494016 )Published on 5/3/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2525835: “MS11-047: Vulnerability in Microsoft Hyper-V could cause denial of service: June 14, 2011” (http://support.microsoft.com/kb/2525835 Published on 6/14/2011 | Yes | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Security Bulletin | |
| KB2550569: “"0x20001" Stop error when you start a Linux VM in Windows Server 2008 R2 SP1” (http://support.microsoft.com/kb/2550569 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| KB2547551: “Hyper-V Export function consumes all available memory in Windows Server 2008 or in Windows Server 2008 R2” (http://support.microsoft.com/kb/2547551 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2568088: “Virtual machine does not start on a computer that has an AMD CPU that supports the AVX feature and that is running Windows Server 2008 R2” (http://support.microsoft.com/kb/2568088 Published on 8/16/2011 | Yes, if you are running Hyper-V on an AMD processor that supports the AVX feature | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2526776: “An update that enables the Windows Developer Preview or Windows Server Developer Preview to be hosted in a Hyper-V virtual machine on Windows Server 2008 R2” (http://support.microsoft.com/kb/2526776 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2586470: “A saved virtual machine crashes on resume when it hits a debugging breakpoint in Windows Server 2008 R2” (http://support.microsoft.com/kb/2586470 )Published on 10/13/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2614122: “Windows Server 2008 R2-based computer may stop responding when dynamic VHDs that are created on the computer experience high I/O activity” (http://support.microsoft.com/kb/2614122 )Published on 10/13/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2608694: “You cannot operate one or more virtual machines in Windows Server 2008 R2” (http://support.microsoft.com/kb/2608694 )Published on 10/20/2011 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2636573: “FIX: The guest operating system may crash when you perform a live migration of Hyper-V virtual machines in a Windows Server 2008 R2 environment” (http://support.microsoft.com/kb/2636573 )Published on 1/10/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Download Center, Windows Update | |
| KB2662288: "A differencing VHD file that is created by using Microsoft iSCSI Software Target 3.3 becomes corrupted in Windows Server 2008 R2 or in Windows 7" (http://support.microsoft.com/kb/2662288 )Published on 2/16/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2587660: "Memory dump file is generated very slowly on a Hyper-V virtual machine that uses Dynamic Memory when the Maximum RAM setting is over 4 GB in Windows Server 2008 R2" (http://support.microsoft.com/kb/2587660 )Published on 2/16/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| KB2661530: "The whole backup operation fails if one out of several virtual machines on a Hyper-V server cannot be backed up in Windows Server 2008 R2" (http://support.microsoft.com/kb/2661530 )Published on 2/16/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| KB2666703: "You cannot restore a virtual machine that has a semicolon in its name or in its directory path on a Windows Server 2008 R2 SP1-based server" (http://support.microsoft.com/kb/2666703 )Published on 3/14/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| KB2665347: “You cannot connect to a virtual machine by using the Hyper-V Manager MMC snap-in in Windows Server 2008 R2” (http://support.microsoft.com/kb/2665347 )Published on 4/11/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| KB2698672: "Pointer in a Linux guest operating system does not work correctly when you rotate the wheel button on the mouse in Windows Server 2008 R2" (http://support.microsoft.com/kb/2698672 )Published on 5/9/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2668084: "Virtual machine is restored in the Saved state incorrectly on a Hyper-V server that is running Windows Server 2008 R2" (http://support.microsoft.com/kb/2668084 )Published on 5/9/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2711771: "Incorrect available space is displayed in a Linux Hyper-V virtual machine on a Windows Server 2008 R2-based computer" (http://support.microsoft.com/kb/2711771 )Published on 6/13/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2711774: "AltGr key does not work in a Red Hat Linux virtual machine on a Windows Server 2008 R2-based computer" (http://support.microsoft.com/kb/2711774 )Published on 6/13/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| KB2712156: "AVX instructions do not work in a virtual machine on a Windows Server 2008 R2-based computer that has an AMD CPU which supports the AVX feature" (http://support.microsoft.com/kb/2712156 )Published on 10/10/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| 2734056: "Alt Gr key does not work on a Red Hat Linux virtual machine after you install the Hyper-V role on a computer that is running Windows Server 2008 R2" (http://support.microsoft.com/kb/2734056 )Published on 8/15/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2, Windows Server 2008 R2 SP1 | Hotfix | |
| 2739143: "Windows 7-based or Windows Server 2008 R2-based computer crashes when you run a guest operating system that has multiple virtual CPUs" (http://support.microsoft.com/kb/2739143 )Published on 9/12/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| 2740390: "Hypervisor does not provide timer services correctly on a Windows 2008 R2-based Hyper-V server" (http://support.microsoft.com/kb/2740390 )Published on 10/10/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| 2744129: "You cannot run a Windows 8-based or Windows Server 2012-based virtual machine in Windows Server 2008 or in Windows Server 2008 R2" (http://support.microsoft.com/kb/2744129 )Published on 10/10/2012 | Yes | N/A | Windows Server 2008 R2 , Windows Server 2008 R2 SP1 | Download Center, Windows Update | |
| 2752183: "You cannot migrate a Hyper-V virtual machine from a non-Bulldozer-based computer to a Bulldozer-based computer in Windows Server 2008 R2" (http://support.microsoft.com/kb/2752183 )Published on 10/10/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| 2755221: "You receive more DHCP logs on a DHCP server than expected after you create a virtual network on a computer that is running Windows Server 2008 R2" (http://support.microsoft.com/kb/2755221 )Published on 10/10/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix | |
| 2740390: "Hypervisor does not provide timer services correctly on a Windows 2008 R2-based Hyper-V server" (http://support.microsoft.com/kb/2740390 )Published on 10/10/2012 | Yes, if the issue applies to you. | N/A | Windows Server 2008 R2 SP1 | Hotfix |
