In the ‘Performance and Maintenance’ control panel, I am running ‘Free up space on your hard disk’ to clean up temporary files. However, the window just sits there and the computer slows to a crawl with the CPU usage at 100%. The computer is running Windows XP.

Provided this problem occurs when you initially open the Disk Cleanup utility during the ‘Scanning: Compress old files’ stage, there is a fix for this problem. There is a good set of step-by-step instructions at the Microsoft Knowledge Base article support.microsoft.com/default.aspx?scid=812248. However, if the problem actually occurs once you have selected that you wish to clean up the temporary files, this could be trickier to solve. Please let me know if this is the case, and I will try to devise a solution. In the meantime, as a temporary work around you can manually delete the temporary files. Firstly, you will need to enable viewing hidden files and folders. Open Windows Explorer and go to the ‘Tools’ menu > ‘Folder Options’. Click the ‘View’ tab and enable ‘Show hidden files and folders’. Click OK. Now navigate to the C:WindowsTemp and C:Documents and SettingsLocal SettingsTemp. These are the two directories containing temporary files which you should be able to safely delete (the files, not the directories).