We have a Windows 2003 Server that crashes relatively regularly (about once every week). At the time the server crashes, there isn't any information in the event logs. Not in Application, not in Security, and not in System. The monitoring system (Nagios) does not report any abnormal conditions on the machine near the time of crash. And when I say crash I mean the server turns off, not merely a blue screen.
I have made some guesses about the cause of the crashes, but so far nothing has proved to be correct. Does anyone know where I can find further information (e.g. logs) or provide any helpful guesses as to the cause?