When I used HDM 14 Suite on Windows 7 I created system images and backed up one HDD containing two partitions (c: and d. The names of the backup files all started with _arc. When I changed to Windows 8.1, I back up two drives, one SSD for c: and a HDD which is d:. The names of the backup files start with img_0 or img_1 now. What is the difference between the _img. vs. the _arc. backups files? I'm "assuming" everything is ok but can't find an explanation for the new backup names. In both Windows 7 and 8.1 I was creating full image backups (not file backups).