Another thought .. since Vista is the beast it is ... with horrible permissions set up, ... try installing LW to a different location, perhaps even a different drive .. making sure you right-click installer run as admin before-hand. I've heard of some people simply creating a folder within the programs folder & installing it within which solved some problems. But the save location during setup might also be an issue.

Other than that, perhaps a program of some kind is clashing with LW on that account. Do you have alcohol on the system? This is known to clash with LW.

Another thought is a security program like a spyware program. Some of them are anti-p2p sharing software. And they will damage the program or prevent it opening properly.

BTW did you get any kind of crash log? That would be helpful. I'm not a windows nut, but I'm sure the system does create crash logs. If you can find such a one for LW crashing, could you post it here as an attachment? Edit out any personal information first.