Why does crysis warhead(pc game) keep shuting down my video drivers?

I was going to suggest updating the drivers but you already stated that you did this. An alternate solution could be lowering all of the video settings in the game. Your video card (in addition to the 1gb of ram) may not be enough to support the game at full quality as well as your high resolution monitor. Sorry if this is not what you were looking for. Best of luck!