XP Mode from previous build will not run on rebuilt PC.

Hi Jeff, welcome to the Seven Forums.

Have you tried to create a new Virtual PC virtual machine selecting the option to use an existing vhd (step 10 in this tutorial), using the old XP Mode vhd as the "existing vhd"?

Kari

What do you mean by "rebuild"? Why do you have to do it so often?

OK, it's a RAID array you rebuild.

After rebuilding and reinstalling Virtual PC, did you also reinstall the XP Mode?

By default the XP Mode uses two vhd files, the base which contains the system core and your personal XP Mode vhd which contains the installed software, your personal files and so on.

If the base vhd is missing, as it is if Virtual PC is reinstalled without reinstalling the XP Mode, and you create a new vm using your old Windows XP Mode.vhd as an existing vhd, you only have (to put it very simple) half of XP Mode, the personal half, while the system core is missing. It's about the same than trying to boot Windows 7 machine after deleting the Windows\System32 folder.

   Information

By default, XP Mode virtual machine consists of five files when installed and run first time, plus two additional files if XP Mode is hibernated or the Undo Disk feature is enabled. The file names, extensions and default locations are:

• Windows XP Mode base.vhd
  
  • XP Mode base disk
  • default location C:\Program Files\Windows XP Mode
• Windows XP Mode.vhd
  
  • Virtual Machine virtual hard drive image
  • default location C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines
• Windows XP Mode.vmcx
  
  • Virtual Machine description and registration settings
  • default location C:\Users\Your_Username\Virtual Machines
• Windows XP Mode.vmc
  
  • Virtual Machine settings file
  • default location C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines
• Windows XP Mode.vmc.vpcbackup
  
  • Virtual Machine settings backup
  • default location C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines
  
  
  Additional files, only exist when certain criteria is met:
• Windows XP Mode.vsv
  
  • Virtual Machine saved state file (hibernation data)
  • default location C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines
  • This file exists only when XP Mode is hibernated or is running. It is deleted automatically every time XP Mode is shut down
• VirtualPCUndo_Windows XP Mode_X_Y_ZZZZZZZZZZZZZZ.vud
  
  • Virtual machine Undo-disk (X, Y & Z in the file name are replaced with digits)
  • default location C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines
  • This file exists only if so called Undo Disk is enabled in XP Mode settings

(Source: Virtual XP Machine - Copy.)

You can think the XP Mode base vhd as the system core of XP. To simplify, let's say it contains the Windows folder and startup data. The personal XP Mode vhd of a user contains then the Programs and Users folders, all user specific data (notice: not de facto explanation, but a simplified example).

All software installed by user, all personal files and folders, all individual content is stored on this personal vhd. Another user on same computer uses the same XP base system, customizing his own XP Mode again using the personal vhd.

XP Mode base cannot be used alone as it has no user, nothing but core XP. The personal vhd cannot be used alone as it has no Windows core.

Let's say I would need to reinstall Seven but save my XP Mode from old installation. The procedure is quite simple:

• I'll back up my personal XP Mode vhd
• Reinstall Seven
• Install XP Mode first
• Install Virtual PC
• Create a new virtual machine using my backed up XP Mode vhd as existing vhd per instructions in this tutorial (Step 10): Windows Virtual PC - Create Virtual Machine

That's it.

Kari