I have recently started using Acronis True Image, version 9, build 2337. I was previously running version 8, build 937. The reason I've upgraded is so that I can create differential image backups. With version 8, I had been creating incremental image backups. I created one full image backup of my C partition to a backup USB drive. I then set up the scheduler to run a daily differential image backup. When I looked at the daily differential image backups, their sizes were what I expected, i.e. each daily differential backup image was slightly bigger than the previous day's backup image. I then had Acronis check the 4th backup (I assumed that it was checking a combination of the original backup + the 4th backup) and it said that everything was OK. I then moved the second and third differential backups to another folder, and then had Acronis check the 4th backup image again. This time, it could not check the image, and insisted that I insert the third backup. Then I attempted to restore a file stored in the 4th image, using only the original full backup and the 4th backup, and Acronis did this with no problem. If I understand the way the program is supposed to handle differential image backups, for either checking images or restoring images, it should only require the original full backup + one differential backup. Is this a bug in the image checking part of Acronis True Image or is Acronis effectively creating incremental backups, i.e. each differential backup is not based on the original full backup, but instead is based on the last differential backup. This would certainly expain why the image checking part of the program requires all the backups. Therefore, if I actually want a daily differential image backup, the only way to do it is to move or delete the previous days differential image backup before the new one is created. This is assuming that the scheduler is not keeping track of the previous differential backups; if it is, then I'm not sure what will work - possibly manually creating each day's differential backup, after I move the previous day's differential backup to another location.