Using XP Mode to test - how to discard changes?

Unfortunately, Virtual PC, the virtual software that XP Mode VM is run from doesn't support saving snapshots. It's possible to do but you have to find the VHD file created by XP Mode and save a copy of it somewhere. When you're done experimenting, you can shut the VM down and copy the saved VHD file back (replacing the current VHD file) and restart the VM and it will be back to it's original state.

You could save copies of the different states of the VHD and copy them in and out.

The VHD file is created in "C:\Users\[your username]\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines"

glnz said:

OK - I have learned it's the Undo Disk setting, which I have now tried successfully.

Is this the only way to turn off without saving the changes? No snapshots so I can save more than one state?

Thanks.

strollin said:

Unfortunately, Virtual PC, the virtual software that XP Mode VM is run from doesn't support saving snapshots. It's possible to do but you have to find the VHD file created by XP Mode and save a copy of it somewhere. When you're done experimenting, you can shut the VM down and copy the saved VHD file back (replacing the current VHD file) and restart the VM and it will be back to it's original state.

You could save copies of the different states of the VHD and copy them in and out.

The VHD file is created in "C:\Users\[your username]\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines"

The posts I quoted above basically already lists all your options. You found out about Undo Disks by yourself, and Strollin's excellent advice about copying XP Mode VHD and restoring it when you need to go back, these are about your only options. I Like XP Mode very much but let's face it, Windows Virtual PC is quite limited.

I have nothing to add, just to suggestion for a practical and quite easy way to "play" with backing up and restoring the XP Mode. Honestly, I am not sure if you will see it "practical and quite easy" as I do but this is how I do this when I need to do something, test something and then go back to old XP Mode.

First, I think it's important to understand the complexity of XP Mode, how it needs several files to really function. Here's a list of all XP Mode files and their default locations:

   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, contains the core elements of operating system (XP), no user data is saved on this virtual disk
  • default location C:\Program Files\Windows XP Mode
• Windows XP Mode.vhd
  
  • Virtual Machine virtual hard drive image, all user data and content is saved on this virtual disk
  • 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. In emergence situations you can force XP Mode to reboot instead of waking up from hibernation simply by deleting this file while XP Mode is closed, then restarting XP Mode
  
  
• 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

My way to do this is to set up XP Mode first as I'd like to have it and when ready, copy the Windows XP Mode.vhd from C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines to a safe location, then when a need arises to get back to my starting setup I simply create a new virtual machine using my backed up Windows XP Mode.vhd file as existing vhd.

When doing this, Virtual PC checks the vhd file and when it realizes that it's not a vhd capable of working alone but instead a differencing vhd needing its base, Virtual PC automatically attach the needed Windows XP Mode base.vhd to it and creates a fully functioning new XP Mode virtual machine. The process, creating a new vm takes just a minute or two. When ready, I will test the new XP Mode and when (if) it works I can delete the files belonging to the old XP Mode, including the old original XP Mode vhd.

Creating a new vm in Virtual PC using an existing vhd, see Step 10 in this tutorial: Windows Virtual PC - Create Virtual Machine

Kari