Sometimes the byte counts for data that you restore don’t match the byte counts indicated when the data was initially backed up. When data backed up from an NTFS volume is restored to an NTFS volume, the byte count will match between the backup and restore operations. However, when data backed up from a NTFS or FAT volume is restored to a FAT volume, the byte count restored is expected to be less than that backed up. The reason for the discrepancy is that the Windows returns a default ACL (access control list) for FAT data; the stream of data is backed up (and the bytes are counted) but is discarded during a restore (and the bytes are not counted).