So I had a main server crash and had to set up a new one...restoring old data/etc. Once I set it up I had to set up a new exchange server...or try to...as I tried to DCPROMO it it won't. Giving me the 5171 event ID. Which I looked up. I've tried the netdiag.exe /fix. It shows the same deregistration failures that are shown happening in the System log. The System log gives an error ID of 5775: NETLOGON...Dns operation refused...deregistration didn't work...etc. Any extra suggestions would be appreciated.