I upgraded Parallels 3 to the accursed Parallels 4 today. I am obviously short on brains and long on action.
Hal, hal where are you? I now have the same situation as I did after a previous Parallels upgrade: a missing or corrupt hal.dll.
I recall that I have a recent Winclone copy of my nasty windows OS. I plan to use that cloned copy to step back in time to before the curse of Parallels 4 struck. Wish me luck!