windows xp mode could not be restored because of either host processor type mismatch

C:\Users\ (Username)\ AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines directory
I: To rename the file *.vsv, follow the steps mentioned below.
1. Click on Start and click on computer.

2. Go to the following location:
C:\Users\ (Username)\ AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines directory
3. You’ll find a .VSV file in the Virtual Machines Directory.
4. Rename the file.
For example: If the file name is VM.vsv, rename it toVM.old


http://answers.microsoft.com/en-us/windows/forum/windows_other-windows_update/error-windows-xp-mode-could-not-be-restored/eac629ec-f789-477e-b69a-ab175ccb8d3a