I have tried several times... I have TI scheduled to make a full back up on Sundays and then differential back ups every other day of the week. I have noticed that the the differential back ups are the same size if not just a little smaller that the complete full back up. I thought it was because of defrag but I made sure that the drive that my backup goes to is not been defragged. What else could cause such problems or is this how the differential works in TI? Help!