Theres obviously some kind of conflict going on. XP has a very bizarre way of dealing with problems....it restarts??
The first thing to do is to turn this useless feature off... press the Windows key and the pause/break key at the same time or go to control panel and double click system. Click the advanced tab and then click the
"settings" button on "start up and recovery", under system failure un-tick "automatically restart"
This will allow your machine to give you an error message concerning what is going on.....