In another blog, I discussed Windows 7 services that you might wish to disable when going down the path of desktop virtualization. In this article, I’m now focusing on registry modification you will want to make to optimize Windows 7 for virtual desktops. I’ve broken it down into Recommended configurations, Standard Mode configurations (for Provisioning services), and Optional configurations.
As I learn more from upcoming Windows 7 implementations, I’ll be updating the following tables, so it might be worthwhile to stay updated with RSS or subscribe via Email. Now, for the good stuff…
Recommended Configurations
The following registry changes are recommended for all deployment scenarios and would almost always be desirable in a Windows 7 hosted VM-based VDI desktop implementation:
| Configuration | Optimizer | Registry Modification (in REG format) |
| Disable Last Access Timestamp | Yes | [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem] “NtfsDisableLastAccessUpdate”=dword:00000001 |
| Disable Large Send Offload | No | [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BNNS\Parameters] “EnableOffload”=dword:00000000 |
| Disable TCP/IP Offload | No | [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters] “DisableTaskOffload”=dword:00000001 |
| Increase Service Startup Timeout | No | [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control] “ServicesPipeTimeout”=dword:0002bf20 |
| Hide Hard Error Messages | No | [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Windows] “ErrorMode”=dword:00000002 |
| Disable CIFS Change Notifications | No | [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer] “NoRemoteRecursiveEvents”=dword:00000001 |
| Disable Logon Screensaver | No | [HKEY_USERS\.DEFAULT\Control Panel\Desktop] “ScreenSaveActive”=”0” |
Note: The Optimizer column indicates whether this registry change is included in the XenConvert Optimizer tool that is installed with the Provisioning Services target device software.
Standard Mode Recommended Configurations
The next set of registry changes are recommended for images deployed using standard mode vDisk images with Citrix Provisioning services. Standard mode images are unique in that they are restored to the original state at each reboot, deleting any newly written or modified data. In this scenario, certain processes are no longer efficient. These configurations may also apply when deploying persistent images and in many cases should be implemented in addition to the changes recommended in the preceding section.
| Configuration | Optimizer | Registry Modification (in REG format) |
| Disable Clear Page File at Shutdown | Yes | HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management] “ClearPageFileAtShutdown”=dword:00000000 |
| Disable Offline Files | Yes | [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\NetCache] “Enabled”=dword:00000000 |
| Disable Background Defragmentation | Yes | [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Dfrg\BootOptimizeFunction] “Enable”=”N” |
| Disable Background Layout Service | Yes | [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\OptimalLayout] “EnableAutoLayout”=dword:00000000 |
| Disable Bug Check Memory Dump | Yes | [HKLM\SYSTEM\CurrentControlSet\Control\CrashControl] “CrashDumpEnabled”=dword:00000000 |
| Disable System Restore | Yes | [Software\Policies\Microsoft\Windows NT\SystemRestore] “DisableSR”=dword:00000001 |
| Disable Hibernation | Yes | [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Power] “Heuristics”=hex:05,00,00,00,00,01,00,00,00,00,00,00,00,00,00,00,3f,42,0f,00 |
| Disable Memory Dumps | Yes | [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CrashControl] “CrashDumpEnabled”=dword:00000000 “LogEvent”=dword:00000000 “SendAlert”=dword:00000000 |
| Disable Mach. Acct. Password Changes | Yes | [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters] “DisablePasswordChange”=dword:00000001 |
| Redirect Event Logs | No | Set appropriate path based on environment.
HKLM\SYSTEM\CurrentControlSet\Services\Eventlog\Application] [HKLM\SYSTEM\CurrentControlSet\Services\Eventlog\Security] [HKLM\SYSTEM\CurrentControlSet\Services\Eventlog\System] |
| Reduce Event Log Size to 64K | Yes | HKLM\SYSTEM\CurrentControlSet\Services\Eventlog\Application] “MaxSize”=dword:00010000 [HKLM\SYSTEM\CurrentControlSet\Services\Eventlog\Security] [HKLM\SYSTEM\CurrentControlSet\Services\Eventlog\System] |
Optional Configurations
This last set of machine-based registry changes is optional regardless of whether the image is deployed as a persistent or standard image. In many cases, the following configurations should be implemented; however, these configurations should be analyzed for suitability to each unique environment.
| Configuration | Justification | Registry Modification (in REG format) |
| Disable Move to Recycle Bin | Although the recycle bin will be deleted on subsequent reboots, disabling this service altogether might pose a risk in that users will not be able to recover files during their session. Although this setting is part of the optimizer, it might be advantageous to not disable the Recycle Bin. | [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\BitBucket] “UseGlobalSettings”=dword:00000001 |
Note: These are only recommendations. You should implement these at your own risk
Daniel – Lead Architect
