Volumn Shadow Copy

1. VSS
2. Volume Shadow Copy
3. Manages and implements Volume Shadow Copies used for backup and other purposes. If this service is stopped, shadow copies will be unavailable for backup and the backup may fail. If this service is disabled, any services that explicitly depend on it will fail to start.
4. C:Windowssystem32vssvc.exe
5. http://en.wikipedia.org/wiki/Shadow_Copy