I have a boot-leg copy of MSTS that I have installed on an XP system. I also got a short-cut that allows me to run the sim without the disk installed. Before you tell me how lucky I am, let me tell you what the problem is. While running the sim with or without the operating disk, my computer restarts. It seems to be random, I can find no pattern of behavior that results in restart. I have played for as long as an hour or as little as 3 minutes. I have been in the cab view, overhead view from the front and rear, and once from the passenger view. Everything seems to be great, graphics and scenics are crisp and smooth, but it just restarts. No error message, no freeze frame, no big whoop, just one moment driving the train, next moment... 'BEEP' ... COMPAC ... "windows is starting" ... It is very interesting and a bit frustrating. I have searched the MSTS message boards on the fan site and found nothing resembling this problem. Any ideas?