1. Boot Windows in Safe Mode and Go to "My Computer" - "C" Drive - "Program Files" - "Parallels" folder and delete the "Parallels Tools" folder.
2. Click the Windows "Start" menu -> "Run" and type "regedit". Hit OK.
3. In Registry Editor, go to "My Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Parallels" and delete the "Parallels Tools" entry.
4. Reboot Virtual Machine and check