Hi Gaieus,
I Think I got it figured out. I did a system restore back to before I downloaded SU8, then redownloaded SU8, and kept SU7 (which I got back with the restore). Now if I open SU8 than close it, my old files that were drawn with SU7 now open in SU8.
Now my question is, do I have to keep SU7 in my computer? Thats were I went wrong the last time. When I removed SU7, I could no longer open any old files. SU8 worked fine and could start a new model, and then reopen it. just couldent open old models that were made with SU7. When 7 was removed, no files showed up in the menu of SU8. The only way I could try to open them was by clicking on them in there folders, and then I would get the "what program do you wish to open this file with" pop-up.