Why Windows server 2012 restars on its own and cant stop restart process ?

Is this a VM? Physical Host? How far in the boot process does it get before it resets?  Have you had a chance to look at logs (assuming it stays booted for a little while)?

With all Windows systems you should be able to hit F8 before startup to dictate startup behaviour - such as boot to safe mode, safe mode with networking, and importantly, stop rebooting if stop error encountered.

Also, is it actually restarting (performing a full shutdown before starting back up again) or resetting?

Wire D wolf
its a physical host.
it resets every few days. can't tell exactly
will check the logs tonight that I get a chance.
I am in a remote location
Will ask those things to technicians in place.
What s the difference between a full shutdown and restart or just resetting? how to detect that?
Noxcho
Configuring for BSOD tonight
Coming back with results in 12 hours...
Thank you, Experts!

GReat testing Blue Screen View too, tonight...
 thank you!

good to know Dr. Klahn
Thank you
Testing now...

... of course since this happens only infrequently, it'll be some time before it's clear what the situation might be.

post the dmp file here for more info
find it in Windows\minidumps

Each advice was so useful !!
Opened a lot of doors also

The main problem is solved
Thanks to all Experts !!!!!