I have recently migrated from domain controllers running server 2008 r2 to server 2012. All seemed to be going ok until I started decommissioning the old servers.
I've got a couple of issues that I'm guessing are related.
1. On the majority of my windows 7 machines, there is about a 2 minute black screen after logon.
2. When I click on a network folder, and go to the security tab the network user sids are very slow to resolve.
I've updated the dns server entries on the computers, I've checked in adsiedit to see if any remnants of the old dcs existed, checked the dns records and removed old dc information...