Just had one weird issue recently and I could not cure the PC from just hanging.
Cant honestly say I have fixed it, but if I told you that the LAN Drivers were stopping the SoundCards Midi/Joy port from working, and this in turn was causing it to hang when it accessed any networking ( i.e tried to log on to the internet ) , you would call me thick, but to be honest with you, I really do think that was it??
trying to do any form of networking would hang the system, and resinatlling the soundCard allowed it to connect but then it was not stable, reinstalling the drivers for the LAN also helped, but then killed off the Joystick port, but allowed me to connect, even though my Modem is USB???? - End of the day, I resorted back to the original CD for the Mobo and hey presto, it then found the soundcard and the USB Modem and its been fine since?
Sometimes just having newer drivers means jack schitt and you sometimes might be worth trying out the older "Tried and tested" drivers.