I have a brand new desktop and I just installed a licenced windows xp profession OS. But the machine shuts down automatically without any notice every several hours. So I reinstalled my Windows XP another time, same problem. I don't know what caused this shut down. I appreciate any help

Since the rig is brand new I would sugest you ring compaq help desk and explain the problem to them. That is what you payed money for. And if I am thinking right the OS should have been installed for you before you even received the rig. Hope that helps Regards IF IT AINT BROKE, DONT FIX IT

It is possible that it is set to go into hibernation within the Power management settings (Control Panel) and it just appears to be shutting off? Bryan

it is possible if the thing has been setup that way. The settings should be in the power options as follows. Power scheme = Home office/Desk Turn of monitor after 20 minutes Turn of Hrad disk = never System standby = Never In the advance tab both options should read Shut Down, or whichever you prefer. Under the Hibernate tab nothing should be ticked. Try that and see how you go. Regards IF IT AINT BROKE, DONT FIX IT