cake: I have had the same/similar issue with disk cleanup and Windows 2000 computers.
Please see the following:
http://support.microsoft.com/kb/886219/en-usIf you are having the same issue as described in this link, please read the warning about making changes to the registry.....
QUOTE
Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
Edit: Typo.