Go to %TEMP% and clean it out. I personally deleted everything older than 5 days. I have no idea why but this fixed an issue for me where it could take up to 3 minutes to get to the desktop after typing my password.

I somehow had like 100s of gigs of garbage in there. Funny enough doing a system cleanup does not clear out this directory!

The issue corresponded with an event in the Windows Event Viewer that looked like:

The winlogon notification subscriber <Profiles> is taking long time to handle the notification event (Logon).

And another that looked like:

The winlogon notification subscriber <Profiles> took 125 second(s) to handle the notification event (Logon).

(of course with a varying number of seconds depending on the boot)

Anyways, I'm not asking anyone for tech support in this case, but figure it may help someone else out.