| - power supply (aka losing voltage) | - all the system fans (aka thermal shutdown) | - memory (run memtest86+ overnight [or longer]) Thanks for your reply. At first, I rule out any fluctuation in power-supply. As far as thermal shutdown is concerned, I don't know how to know if it is the case. However, it is a brand new PC and so, I hope it should be working. But I will check it out properly. memtest86+: I will run it overnight. As David asked: | What do you have to do to get the box out of "suspend?" If the system | is frozen and you have to reboot the box to "unfreeze" it, I'd guess | it's a heat issue. yes, I need to push the power-button to restart it. Thanks once again. I will report the outcome as soon. - Chandra