I sent my computer back to HP. They put a new motherboard in. Got it back. It starts up with a black or blue screen. Takes forever to start up. As long as I am using it everything is fine. If I leave it for a while it freezes up (does this when I turn it on also). I have to turn it off at the modem and restart. The modem makes a loud noise and the orange ligt is not flashing.

If the computer is still under warranty, return it to HP for further diagnosis. The motherboard was apparently not the issue or whatever caused the prior board to fail may have cause the new board to fail as well. Freeze ups or apparent freeze ups are normally due to bad power, bad components, or component overheating. I do not know what you mean by "turn it off at the modem". Is this a computer lockup issue or a network connectivity issue?