Which has me confused as hell, I have 8.5.3 PE, it says I do NOT have to install Disc 3 of X1(Dim. Pro 1.5) if I'm leaving 8.5. By the way, how do you check version of Dim Pro, remember going through 3 or so updates in 8.5. I hope it's OK, I'm not putting Disc 2 in unless I have to. Why make different versions of Dim Pro for X1, or did they, and then have to delete 8.5s, go through all the registry changes???Screw it Im done for a day or two, sorry for wasting a couple peoples time! Maybe I don't need it,(disc 3) of x1 we'll see! Thought I could order discs load em up 1,2,3,4 bam, update to X1c if need be, see ya in a couple weeks. Good luck!