I had similar problems with seemingly random hard lockups. I blamed everything. Then I discovered my PC was getting too hot. Try running with the side off and an office fan pumping air in. If all is stable, buy another case fan. AMD processors are particularly bad for this. They won't lock up except in games. I have a fancy alloy case with 2 exhaust fans and it was still getting too hot. Put a case fan in pushing air in and no problems for 6 months or more.
Try this first, not like me who blames AH, drivers, reinstalled windows, blamed hotas cougar up down all around. Sound drivers blah blah 4 in 1 drivers. What a nightmare it was. Check temp before you go doing all the other stuff everybody tells you. Athlon should be below 50oC. Watch chipset temp too.
Don't know about the other problems.
Good luck:D