blank screen on bootup and Process Guard

Hi I have been having problems with blank screen on startup of the game - after a couple of ctl-alt-dels, i was getting the message "Unrecoverable Graphics Error" and having to close the game tab.

So, I installed the latest nvidia drivers, no joy, reinstalled the game, no joy. Eventually I tried turning off Process Guard which allowed me to go into the game. After tweaking my Process Guard settings, the game now runs fine

So for any of you out there who are getting this sort of problem, it may be worth while checking your security software settings as well as the usual checks; the error message may be misleading - in my case Process guard was stopping Guild Wars using the Physical Memory, but not telling me that.