Why do I have so many VHD files? 3 files but only 1 virtual computer

I have a vhd file with windows xp and it refers to a base file "Windows XP mode base.vhd" in the Windows XP mode folder of program files. Ok, I understand that it is differencing from this file somehow, but I also have a Virtual Windows XP.vhd file in the Virtual Windows XP folder also in program files.

Why does this third vhd file need to be installed?
I am migrating to a 128 gb SSD and would like to keep windows as trim as possible.

I apologize for asking for help on my first post.

Hi rkguy, welcome to the Seven Forums. Ne reason to apologize for asking help, that's the most common reason to join us.


By default, Windows XP Mode has four files after installation:

• Windows XP Mode base.vhd, located in C:\Program Files\Windows XP Mode
• Windows XP Mode.vhd, located in C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines
• Windows XP Mode.vmc, located in C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines
• Windows XP Mode.vmcx, located in C:\Users\Your_Username\Virtual Machines

Two more files, Windows XP Mode.vsv and Windows XP Mode.vmc.backup, are created in C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines when you start using XP Mode. Every time XP Mode is hibernated it creates the said .vsv file, which contains the hibernation information, being similar than hiberfile.sys in a real, physical computer. The vsv file exists only when XP Mode is hibernated. The vmc.backup is as the name says a backup copy of vmc file.

Additionally, you can enable so called Undo Disk. When enabled, an additional file is created, also in C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines. The name of this undo-file is VirtualPCUndo_Windows XP Mode_X_Y_ZZZZZZDDMMYYYY, where X, Y, and Z are digits and DDMMYYYY is the date using 8 digits. Undo disk makes it possible to revert all changes, to undo everything.

If you want, you can relocate the vhd file located in C:\Users\Your_Username\AppData\Local\Microsoft\Windows Virtual PC\Virtual Machines. The base file should not be modified or moved. The vmc and vmcx files are really small text (script) files, taking almost no place. They should not be moved

More to read:
- Windows Virtual PC: Get Started
- Windows Virtual PC - Wikipedia, the free encyclopedia
- http://www.sevenforums.com/tutorials/21904-virtual-xp-machine-copy.html?ltr=V
- http://www.sevenforums.com/virtualization/80378-backup-xp-mode-2.html#post751417
- http://www.sevenforums.com/virtualization/59287-xp-mode-where-does-hard-disk-come.html#post535646

Kari