Describing the problem other than just "Hang" would give us some idea of how to help.
Does this happen in games, CPU intensive activities, opening music?
Have you been monitoring the CPU usage during general use and when it hangs.
Have you run benchmarks such as Prime 95, Furmark and such to test the components are stable?
Have you run MemTest to check if the RAM is failing, same with Disk Checker for the HDD?
What is the specs of your machine and how old is it (particularly the PSU and HDD)?
Is anything overclocked?