[VJunk]

This is an issue with accelerated video drivers and Hyper-V. Microsoft finally addressed it in KB article 961661: http://support.microsoft.com/kb/961661. It seems to be primarily with NVIDIA drivers but I am also experiencing it with an Intel graphics adapter in a Dell Latitude D830 (although the hard drive with this 2008 install was moved from a laptop with an NVIDIA GPU so that might have something to do with it). Switching to a 2008 in-box generic VGA driver fixes the issue but you lose Aero enhancements.

What I do is have the hvboot Hyper-V service set to manual (and therefore not started on boot) so everything runs fine. When I need Hyper-V, I start the service. Graphics performance goes down, but at least I can run Hyper-V. Once running, the service cannot be stopped so I reboot after I am done with Hyper-V.

Since the hvboot service does not appear in the Service MMC, you need to modify the registry directly. You can paste the following into a .reg file:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServiceshvboot]
“Start”=dword:00000003

To set it back to automatic, change it back to 00000001.

To start the service, enter the following at an elevated (run as administrator) command prompt: net start hvboot

[VJunk]

Just want to verify. Cairnz, you are running 2008 R2, have an nVidia graphics adapter, have Aero working, have Hyper-V installed, and are seeing no issues with graphics slowing down when the Hyper-V service is running? With non-R2 2008, because of the way the nVidia drivers are written, enabling Hyper-V slows down graphics performance considerably, particularly when drawing windows or scrolling in pages. Did you ever run non-R2 2008 on this laptop?

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