Are you able to keep the system alive long enough to see the Event Viewer if you restart into Safe Mode?
I recently installed Win 7 64-bit on my wife's Acer Aspire 4520 laptop. The system now shuts down and dumps whenever a key is touched; any key. I cannot tell from the cryptic information provided in the dump what is causing the problem. It didn't happen immediately. It worked for a few days. I suspect it was an update but can't get a clue on where to look. Any help?