System shutdown on boot: software or hardware?

[Mureika, Jonas]

Beginning about two weeks ago, I noticed that my Enterprise Server (WS) running on a Dell Dual Processor machine started to spontaneously reboot.  The problem became more frequent, and this morning I discovered that I cannot boot the system to completion.  The machine is still running, but the video signal to the monitor seems to be cut.  I thought this may just be a monitor problem, but I cannot access the machine remotely either.

Has anyone else experienced similar problems?  Does this sound like a software issue that can be fixed with a patch, or a hardware issue?   The machine is almost 3 years old, and has never given me problems in the past.  Any insight would be very much appreciated.

--JRM