Pentium 4 and Mercury PI865-D7.The pc is stucking when the windows start up is coming up .After reloading windows is back and fine and then again after one day same thing hang and stuck W7.Putting the os to load it also hang, after a bar line complete, the HDD partion also not showing under os loading.I tried with changing of ram and HDD several times.I am a hardware technician as well.Is it hardware fault or software Help me please.