Domain Logins very slow all of a sudden

Single Forest, Single Tree, Single Domain
4 DC's , 2 at corporate 2 at data center, all 4 are GC and DNS
Domain is in 2008R2 mode both domain/forest.

Domain has been running fine for a year all of a sudden every login is taking 3 minutes.  The only information in event viewer on the clients I can find related is :"The winlogon notification subscriber <Profiles> is taking long time to handle the notification event "

DNS 'seems' fine .. replication seems fine.  What am I missing ?  Help !
usmmsupportAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Mike KlineCommented:
Is it taking that long for every user and every machine?   Any changes at all made anywhere?  

Take a look at the links in this blog (and the two I added with my comment)

http://adfordummiez.com/?p=86

What is the event number....I'll see if I can find any more information.

How does dcdiag look on your DCs?

Thanks

Mike
saurabhsehgalCommented:
Please take a look at policy "Always wait for the network at computer startup and logon" under Computer Configuration\Administrative Templates\System\Logon

If enabled, disable it.
refer http://support.microsoft.com/kb/305293

You can also collect userenv logs and upload to diagnose issues issues using http://support.microsoft.com/kb/221833
usmmsupportAuthor Commented:
Found the problem .. stupid stupid, the login script which runs under GPO writes a file to our file server and apparently the file server share was down, something i was NOT looking at for a domain login failure :)  

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
usmmsupportAuthor Commented:
self solved
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Active Directory

From novice to tech pro — start learning today.