Ok, I have an Asus K50ID laptop, when I'm just using the laptop there are no issues, but as soon as I plug in my 2nd monitor (24in) whenever I attempt to do any HD video (720p/1080) after a few seconds-minutes it locks up. No blue screen just locks up completely and I have to hard boot it. It plays HD fine without the 2nd monitor connected. And it's every time no matter what, if I just boot the system and turn on HD video it does it or after I've been surfing for hours. Also this is on AC power or battery power. The only reason I'm even using it with a 2nd monitor is because my desktops raptor drive ate shit and I'm waiting for it to be RMA'd so i can use it again.

Specs:
W7 64bit
Prentium Dual-Core T4400 2.2gh (lol i know slow)
Nvidia 320m 1gb video card
4gb ram

I've updated all the drivers I can, I'm not sure what it is. Maybe it's overheating trying to push hd and support the 2nd monitor? Any ideas are appreciated thanks!