Don't know why but every time I play this as soon as I start to get in to the game and really have fun BAM! This message pops up and takes me to the desktop, but just now I just found the game keeps running where as before it crashed it and tanked the frame rate to -10 levels. However if I keep playing despite the error message and make it to the elevator the game freezes up if I try to go on to the next level

How do I stop this bloody thing from popping up?