Hi, I used True Image Echo Workstation 8.072 to create a full backup. However, as it exceeded one DVD, but only by a little, I decided to backup Part 2 on to my secondary hard drive (I have two physical hard drives). Now, after a few months since then, I would like to create Differential backups. However, I am not sure which part I choose to proceed with this - Do I use Part 1 on DVD, or Part 2 on the hard drive as the reference file for which Acronis asks? Would this even work if I have two separate parts for the original backup image? TIA.