Have a 2008 SQL Server that hung on a Windows update. Its hostname (and SQL instance) was named SERVER1 (example). Its IP was 192.168.1.10 (Example). I removed the server from the network, recrated the RAID and reinstalled the OS and then reinstalled SQL 2008. I did this while off the network. I rejoined it back to the domain and tried to rename the hostname back to SERVER1. I was met with "Account already exists" error message. (it really doesn't)
Reluctantly - I gave up on renaming the hostname back to what it was.
For other reasons for 3rd party applications to work properly - it seems I DO need to change the hostname back. (Lets forget what that will do to the SQL instance) The strange thing is if I go to another properly working server on the same subnet and I do a PING SERVER1 - it responds with Reply from 192.168.1.10 even if the server has no record of the SERVER1 or 192.168.1.10 in the hosts/lmhosts file.
Very confused. I've had similar situations before and not run across this. I've tried it on a few servers in the network so it makes be feel like i shoudl be looking at the domain controllers possibly? I feel like I need to get the domain to forget there was a SERVER1 or delete the entry where it lives so I will be able to change the hostname.