Shadow Copies have been introduced into Windows XP Service Pack 1 and been extended in Windows Vista where it is used in System Restore and backup utility. You might have come upon the problem that a file was in use when trying to copy, move or delete it. Shadow Copies are used to copy every file, basically state of the art read only copies of files on the hard drive. This means that even important system files that are running all the time can be backed up without difficulties.

