Windows XP A to Z - http://www.softwaretipsandtricks.com/windowsxp
Tweaking the Disk Cleanup utility
http://www.softwaretipsandtricks.com/windowsxp/articles/380/1/Tweaking-the-Disk-Cleanup-utility
Super Admin
 
By Super Admin
Published on 02/25/2005
 
When using the Disk Cleanup, if you never want to "Compress Old Files" (which is often annoying and takes a long time)

Tweaking the Disk Cleanup utility

Locate and then click the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches\Compress Old Files

On the Edit menu, click Export, in case you change your mind.

On the Edit menu again now click Delete.

Thanks to Microsoft for this tip:

http://support.microsoft.com/default.aspx?scid=kb;en-us;812930