AD reinstalled issue

I've been playing with a new server stepping into the world of Active Directory and playing with some setting and so forth. Using Server2k3 R2.After setting up the first AD I desided to give a different Domain name for the network. I was trying out some things and if I botched the install to much was going to reinstall the OS.

Well I did the dcpromo cleaned up DNS and ran dcpromo again. Everything is good. but when i run dcdiag /e /test:dns the Delegations (del) fails out and i see the old domain name there. servername.olddomainname.local failure: missing glue A record. Then the newdomain.local everything passes but del fail and Ext N/A. Alot of the test that I run give me the old domain name. is there a way to remove it from the system?

This is a different question but if you just change the default-first-site-name by right clicking on it, there is nothing else that has to be configured right?

 

I figured it out, the msdcs > Name server in DNS domain still got the old Domain information instead of the new. I wiped out the DNS files before loading AD, but still got the the old domain info. This corrected the issue and now DNS is working properly.