madami eh...hangs can be caused by a lot of factors, namely drivers, yung operating systems mismo, installed applications or even the hardware.

hanggang ngayon may tinitira kaming PC dito sa office na naghahang din. among the activities that we have taken:

a) checked the cables inside. ok naman.
b) checked the system for virus. although may nakita na Trojan, nung natanggal, naghahang pa din.
c) since may nakitang virus, we assumed na baka may tinamaang DLL sa OS. so we repaired the OS. naghahang pa din.
d) we decided to clean format and clean install the OS. ganun pa din.
e) we have checked the RAM for loose connections. Ok naman.
f) we isolated a defective USB port. so assuming na yun ang nagiging cause, pinalitan namin ng USB. ganun pa din.
g) yun pala ang problema is yung CMOS...