A new, compelling feature in Windows Server 2003 is the Shadow Copies service, which enables you to create "point-in-time" snapshots of the data on your disks. This service is available only on NTFS volumes.
To create a shadow copy of a volume, open My Computer, right-click a disk volume, and choose Properties. Select the Shadow Copies tab. To enable shadowing on a twice-a-day schedule, click Enable. The shadows will be written to the same volume that's being shadowed.
By default, the service uses up to 10 percent of the space on the volume. For slightly better performance, you can locate the shadowed information on a different drive by clicking the Settings button, and then change the Located On This Volume option to the drive on which you want to store shadows. Microsoft highly recommends that you keep shadows on a different drive for servers with heavy I/O.
To allow client computers to use the shadowed files to recover a file they accidentally deleted or overwrote, install the client software that's located on the server at \\%systemroot%\system32\clients\twclient. On the client, a shadow copy is referred to as a previous version.
Note: A shadow copy isn't a suitable replacement for a backup solution, because it doesn't provide long-term recovery or recovery of system files.