A few weeks ago after some Windows updates were deployed through WSUS, Windows has become very slow to boot. At first it appears as though it's trying to process a start up script, but nothing is logged in event viewer regarding any group policies and slow processing, the only thing that does appear is this:
"The winlogon notification subscriber <GPClient> took xxx second(s) to handle the notification event (CreateSession)"
It takes over an hour to get from the initial Applying Group Policy Settings screen to the login screen, and when rebooting takes a few minutes at Shutting Down Service: Group Policy Client.
Things I have tried:
Installing Windows 10 fresh in a clean OU, then applied all the policies one at a time to mirror our standard structure. Windows booted fine, until I ran Windows update that installed some security updates, after that I got the slow boot.
Then I tried a fresh install, installed all the updates, and then applied the policies, and the machine was fine, no slow boot.
I am now going through trying to uninstall updates, but Windows won't let me uninstall the security updates and I fear it may be one of those causing the issue.
So it seems that whichever update it is (if it is an update causing the problem) if the update is installed before group policies are applied then there is no issue, but if the update is installed to a machine that already has policies, it causes slow down.
Now I could build a new image and capture in WDS, but then I'd have to go round 1000+ computers and re-image them again!
Has anyone else experienced this issue and maybe a fix?