/Shadow=ShadowId /ForceDismount /Quiet - Reverts a volume to its state at the time of the shadow copy. All shadow copies ...

%1 %2 /Shadow=ShadowId [/ForceDismount] [/Quiet]      - Reverts a volume to its state at the time of the shadow copy.      All shadow copies of the volume taken after that point will be      removed.  All changes to files and folders on the volume made      after the time of the shadow copy will be permanently lost.      The revert operation cannot be undone.  Once the revert      operation is started, it cannot be canceled.  If any handles      are currently held on the volume, the revert will fail unless      the ForceDismount flag is specified.        Example Usage:  vssadmin Revert Shadow                               /Shadow={c5946237-af12-3f23-af80-51aadb3b20d5}                               /ForceDismount