I think I know what is happening, but I don't know how to deal with it. Your game more then likely can't read 160 gigabytes as anything higher then probably something like160 MB. I posted your message over at GameBoomers Forum for tech help at:
I also know nothing about Vista and a number of those folks at GameBoomers do. You should go over and see what they come up with. They may want to ask you questions and give you some suggestions to try.