After you install Windows 7 SP1 you'll notice an additional entry in Disk Cleanup for cleaning up the backup files. Once cleaned up, the entry still remains in Disk Cleanup. to remove: Delete 'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches\Service Pack Cleanup' or use: forums.mydigitallife.net/attachment.php?attachmentid=8372&d=1297343751 Source: mydigitallife.net/2011/02/11/delete-service-pack-backup-files-entry-in-disk-cleanup-for-windows-7/