Remove Checking for compressed file while disk cleanup

On an NTFS partition, Disk Cleanup can compress old files
to save space. But calculating the savings and performing
the compression often take a long time, and on some systems,
Disk Cleanup hangs during the process. If that happens, or if
you don't care to wait, use this Registry tweak to disable the
compression:

In start menu click on run and type regedit

Go to-->

HKEY_ LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
CurrentVersion\Explorer\VolumeCaches\Compress Old Files

delete The Compress Old Files key.

I dont think this tweak works in Vista.