I have a Xeon server with an Intel S3200SH board. I have an issue where Hyper-V is broken by a registry key permissions issue (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E97D-E325-11CE-BFC1-08002BE10318}\Properties).
After weeks of research I found this out by reading this TechNet article:
Virtual Machines Fail to Start, cannot add disks <failed to add device 'Microsoft Virtual Hard Disk'> <Failed to power on with Error 'General Access Denied Error'>
You'll have to Google that article title, MS won't let me post links (thanks very much).
HOWEVER, the registry key at fault keeps regenerating every time after I delete it, causing the Hyper-V issue to start over. I cannot make any progress until I can ensure this doesn't recur. Any help greatly appreciated.