VSS Restore State
During a restore operation, the requester can use the IVssBackupComponents::SetRestoreState method to define the type of restore operation in progress. However, most restore operations will not need to override the default restore type (VSS_RTYPE_UNDEFINED). Writers should treat this restore type as if it were VSS_RTYPE_BY_COPY. For more information about restore type values, see the VSS_RESTORE_TYPE enumeration.