I am using Windows 2008 R2 server for my Active Directory Server. Recently it started shutting down every 1 – 2 hrs for no apparent reason. Upon some analysis, I found out that it is because the Operating system was expired.
So to resolve this issue, we need to rearm it and it will not bother you for next couple of days.
a) Go to command prompt and execute below command.
c:\windows\system32> slmgr.vbs -rearm
2) Reboot the server and it should not give you trouble for next few days.