You might encounter this error message when you attempt to use the c:\windows\system32\osuninst.exe command and either of the following conditions exists on your computer:
- The Undo folder isn’t present on the system.
- The Win9xundodirpath and Win9xundointegrityinfo registry values are not present in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup registry subkey.
The Undo folder is typically located at the root of the C: drive and contains hidden and system attributes. To view the folder from the recovery console or command prompt, you need to type
or set the folder permissions by typing
attrib -sh c:\undo
If the folder is missing, you can’t uninstall the OS.
If the registry information is missing, try restoring a previous registry backup. Again, if this information is missing, you won’t be able to uninstall the OS.