Volume Shadow Copy (VSS) isn't exactly new in Vista, just better exposed. Windows XP offered the same feature but a "Previous Versions" client which would allow users to take advantage of the backups had to be deployed. Vista includes this Previous Versions client by default.

It does not replace backups, but it is a very helpful intermediate service for getting back deleted, replaced or somehow corrupted files. By default of VSS, the Previous Versions client, available along with the VSS, users and administrators can have access to these snapshots. While you had to deploy the Previous Versions client on Windows XP, it is built into Windows Vista and WS08.

The way VSS works is by using a "write forward" procedure. Instead of replacing an existing file, VSS creates a new file in available space and points to the original location for previous versions as long as that space is not overwritten. Shadow copies are created when restore points are created, typically once per day.

While you can get see the previous version of an existing file by right-clicking and choosing "Properties" and selecting the "Previous Versions" tab, how to restore a deleted or renamed file may not be so obvious, so here goes:

1. Locate the folder that contains the file or folder that was deleted or renamed in Windows File Explorer (explorer.exe).
2. Right-click somewhere in the folder (without selecting a file or folder), and then click Restore previous versions.
3. Double-click a previous version of the folder that contains the file or folder you want to restore. (For example, if a file was deleted today, choose a version of the folder from yesterday, which should contain the file.)
4. In the folder, simply click and drag the file or folder that you want to restore to another location in order to restore it to that location.