About 2 years ago we properly decommissioned a 2008R2 DC. DC promo was ran, server demoted, then we removed AD from the system. The DC was the fsmo role holder. We transferred all the roles 2 weeks before the decom. We ran netdom query fsmo from each DC and they all reported the new DC was indeed the role holder.
We ran through adsi and DNS to remove any remnants of the old server. Netdiag and dcdiag checks all good afterwards. We ran repladmin tests to make sure there were no sysvol issues.
We recently made some major AD changes including a domain rename. Ran through all the proper rename steps and even ran rename /end. All users could log in, all server shares and namespaces were working, not a single user reported an issue. We were happy.
A few weeks later we noticed some updated GPO's were not being applied. Mainly the folder redirections.
gpresult /v shows the group policy is being applied from the old 2008 server that was decom'd years ago. When we run gpupdate /force user policy will not update because the system cant figure out which forest the computer/user is in.
On a few test machines, we unjoined the domain and rejoined. Same issue. We did it again and changed the computer name (same issue). User processing will stioll not run and again group policy is applied from the old 2008 server.
Something is pointing to the old DC somewhere but i cant find it. Every computer on the network says policy applied from that 2008 server.
Where should I look?