Running: SBS 2003 SP2 with Exchange SP2, Bit Defender AV Console
It started about three days ago, the server froze (no mouse or keyboard inputs, but still could ping it but not remote to the server) and had to manually restart it. Profile would not load, so in Safe Mode disabled all Exchange services, server came back on, started the services and things were running OK, then in the middle of the day the server rebooted itself and came back online without any problem. Again today at midnight server stopped responding and had to shut it down, came back on with no problem.
What I've done so far:
Ran HP Smart Update and installed all (33) latest drivers and BIOS for all the components
Event Logs don't show any critical errors, right before the unexpected reboots, only ID 11 Source PlugPlayManager
All Windows Update are installed
The only major change that was made on the server was installation on Bit Defender server, but it could be just a coincident
Need some advice what else check and do?