Audio problem in windows server 2008

I have installed windows server 2008 on virtual PC 2007.

I have audio driver which works fine in Vista but it does not work in Server.
The driver installation runs fine (setup.exe), no errors reported
whatsoever, after installing setup ask to restart Windows.
After rebooting there is not audio driver installed.
Audio services also have been enabled.
it can detect the sound card but after driver installation also it shows no driver installed.
I have already added the roles such as Desktop Experience and Quality Windows Audio Video Experience, But no help.
Please help ASAP.
MD Aslam