Hi, 
I have the same problem with my HD 7870 King poker edition, i tried everything on the above, i uninstalled the catalyst control center including de amd drivers, i went to save mode used the DDU program, back to normal mode and installed CCC again including the drivers, then back again because the problem still exist, but now i used driver booster in stead of CCC, i minimized my memory use, i stopped my antivirus, used the microsoft fixit, updated windows, i even tried to use high and low settings in- game but i keep having the freeze screen and the report. also like above it happens regularly during one hour of gaming, i have an intel i5 of almost 2 years old 8g of ddr3 ram and windows 7, please help me im starting to get desperate and thinking about buying Nvidia.