Automated system recovery
Automated System Recovery (ASR) is a windows tool used to simplify recovery of a server's system or boot volumes. ASR consists of two parts: an automated backup, and an automated restore. The backup portion can be accessed in the Backup utility under System Tools.
ASR does not backup user's files or other data, only data neccesary for restoring the system configuration state. Other backup systems should be put in place to ensure user's actual data files are also backed up. In the event of a failure an ASR backup is performed first, which allows user files to then be recovered.
ASR should be used only as a last resort because in preparation for a restore ASR will format the system and boot volumes of the hardrive, making other, less drastic recovery methods impossible.
References
Automated System Recovery overview in Windows XP
Recover with Windows Automated System Recovery