First I tried the windows 7 crash fixes stickied above and it kept happening

What happens is when I die and sometimes before I die in a battle the screen freezes but the sound continues... it never unfreezes and I have to hard reboot I cannot even alt tab out or windows key out.



System Specs

Windows 7 ultimate x64
16 GB of 1600mhz ram
AMD 6970 Graphics
AMD 1100T processor


Any thoughts on how this crash can be fixed?