Parallels

Symptoms

When I try to start my virtual machine after upgrading from Parallels Desktop version 3 to version 4 I see the warning about  Agp440.sys service followed by BSOD.

Resolution

Please perform the fix described at Microsoft Knowledge Base: http://support.microsoft.com/kb/324764

To do so,
1. Stop the virtual machine (VM)
2. Attach a Windows installation CD to it (click Devices -> CD/DVD-Rom).
3. Go to Virtual Machine -> Configure menu. Browse to CPU tab. Make sure that the "Show advanced settings" checkbox is enabled in the bottom-left corner of the window.
4. Type

vm.compat_level=2

in "System Flags" field.

5. Close Configuration and start the VM.
6. Capture input and press any key to boot from CD.
7. Perform the actions described in Microsoft KB article given.
8. Stop the VM.
9. Go to Virtual Machine->Configure menu. Browse to CPU tab. REMOVE the "vm.compat_level=2" string. Close Configuration menu and boot the VM.

After that restart the VM and complete the upgrade. Now it should be performed fine.