A few days ago I “upgraded” to Parallels 5. I have multiple XP environments and one of them refused to start and was giving me the blue screen of death. Here is my mistake: I tried to resolve the issues appearing on the blue screen. If this happens to you don’t try to solve these issues. It iwll get you no where very slowly. I did find this post though: http://reviews.cnet.com/8301-13727_7-10392166-263.html. It it turns out this is a known issue and easily be remedied. That is too late for me know, since I tried a repair on my vm which means might as well rebuild it now, hopefully though it is not late for you.