I have two Windows 2003 Domain Controllers here, and one of them is restarting unexpectedly about 2-3 times a day. I can't find anything in the logs that points to the cause, and virus scans cone up totally clean. The only reason I even found out is because I was browsing the logs on my Exchange Server and kept seeing a cluster of errors saying that <mydomaincontroller> was shut down or not available for the reboot period. Where do I start troubleshooting THIS one!?