One of our school sites is all Windows 7. We have one AD domain in our environment. Over the summer, I upgraded our DC's to Server 2012. When this school site started in July, they were experiencing 30 minutes to an hour wait on the Welcome screen (pressing Ctrl-Alt-Delete did not break out of this). We started doing some troubleshooting and found that there was a printer trying to be pushed out via GPO that was no longer on the print server. We removed that, and logins sped up for about 2 days, but then slowed back down. We removed all the printers from group policy, thinking it had to do with printers, and the logins sped back up. We started adding the printers back in to group policy one at a time. After about 8 were added, the login times slowed down again. We dropped back down to just having 5 printers being pushed out, and login times sped up. This lasted for about 1 day, than they slowed down again. We completely removed all GPO's from that site and things sped up again for about a day. I got a firm of Microsoft engineers involved. They couldn't find anything on the computers that pointed to a problem. They did find a bunch of replication errors on the local DC and suggested that I build a new VM and create a new DC. I did this, but it had no effect. I have also downgraded the DC back to 2008 R2 with no affect. Last week, we found another problem in the GPO and fixed that. Things sped up for one day and then slowed down again. We have deleted all profiles off of a machine, in case they were corrupt, but still had the same problem.
Some things we have found in our almost 2 months of troubleshooting:
1) This only seems to affect student accounts at this site (but not all accounts are affected. It is very sporadic). I can log in with students from other schools and don't experience the problem. Neither is there a problem when I or any of our techs login (none of those accounts are in this school container).
2) If we let the computer sit at the Welcome screen until it finally logs in, we can logoff/reboot and login immediately with that same account. But that account will experience the slowness on another machine until we let it sit there. (This, of course, is not a viable solution for the problem as the teachers don't have the time in class to do this.)
Currently, I have moved all of the students out of their current container, so no GPO's are being applied to them (except the default domain controller policy). I have created a vbs script that maps their shared drive and some printers. I just did that this morning and am waiting to hear if they still have the problem. Additional Info: I have heard from the school this afternoon, and they did not experience any slow logins.
Any ideas would be appreciated. We're at a loss here.