Problem Statement:

I got my server rebooted automatically. How can I check the root cause of the reboot?


You can easily check the server logs for all events including the server reboot.
  1. Login to the server as an Administrator
  2. Go to > Start >> All programs >> Event viewer
  3. Expand the Custom Views >> Administrative Events

You can find the root cause of the reboot. If such issues arise eventually, you can search/install hotfixes provided by Microsoft for such issues.