If you have an OEM preinstalled version of Windows XP, you may loose data and settings from the All Users and/or Default User folders, Startup group shortcuts, documents, pictures, and music files, from the Shared Documents folder, when you perform any of the following:
1. You reinstall into the same folder:
You press Upgrade (Recommended) after running Winnt32.exe.
Your press Install Windows XP on the CD-ROM's Welcome to Microsoft Windows XP screen.
You perform an in-place upgrade using any method.
2. You run a repair from the CD-ROM.
3. You upgrade the Home Edition to the retail version of Windows XP Professional.
The only solution is to restore the data.
To prevent this behavior, delete the %Windir%\System32\Undo_guimode.txt file, NOW, and every time you first logon after performing any of the above functions, or if you use the Restore CD-ROM provided by the OEM.
NOTE: Microsoft may eventually release a Critical Update to prevent this behavior.