I've noticed that in some cases where we've renamed systems and they reboot, the systems will register the old and new computer name in DNS. Here's an example from the DHCP logs
11,08/13/15,07:46:55,Renew,10.17.205.223,5TH-86032.mydomain.com,9C8E99DE5F7F,,3179929243,0,,,
32,08/13/15,07:46:55,DNS Update Successful,10.17.205.223,HOC-86032.mydomain.com,,,0,6,,,
32,08/13/15,07:46:55,DNS Update Successful,10.17.205.223,5TH-86032.mydomain.com,,,0,6,,,
The new name is 5TH-86032 but the old name, HOC-86032, is still registering. I can't figure out how to prevent this. This HP systems have vPro enabled on them so that may be a possibility.
Orange County District Attorney