RS-Prerelease build 21343 is out to Dev Channel

No. Windows defender. 

@SpiderG, 

Hi, did you manage to get the latest update or are you still getting the error 0x80070643  ?

page 3, of course...

Decided to go back to the previous build. Unfortunately, Quick-access items didn't return, however, from log-in to desktop is back to instant

I am only finding this delay on the first login of the day. Subsequent restarts are normal.

Didn't make any difference on mine, all subsequent log-in's were similar

@Vienna10, 

I restored Dell XPS 8300 to previous build 21337 and, as you said, the delay on login is gone and the taskbar on the left side is already fully populated when it gets to desktop. 

Also the same machine has dual boot to 19042.870 and there is no delay on that build either.

page 3, of course...

Decided to go back to the previous build. Unfortunately, Quick-access items didn't return, however, from log-in to desktop is back to instant

I am only finding this delay on the first login of the day. Subsequent restarts are normal.

@Silverpulser, 

4 different machines at 21343 show this excessive delay on every login or sign in after a sign out.

Over 30 seconds in some cases and the taskbar has a delay populating too.

https://aka.ms/AAbnm8y

UPDATE - Just completed a Dell Inspiron bios update and yes it took  30 seconds from the sign in screen to the desktop and populating the taskbar.

page 3, of course...

Decided to go back to the previous build. Unfortunately, Quick-access items didn't return, however, from log-in to desktop is back to instant

I am only finding this delay on the first login of the day. Subsequent restarts are normal.

@Silverpulser, 

4 different machines at 21343 show this excessive delay on every login or sign in after a sign out.

Over 30 seconds in some cases and the taskbar has a delay populating too.

https://aka.ms/AAbnm8y

Please report the issue in the Feedback Hub,

include a Capture and share the link here for

Eddie (MSFT) to see.