Windows update causing trouble with "unifying" receiver

Hello, i just reinstalled windows 7; first i installed all my apps, and later on the windows updates : before that, no issue at boot, but after : between "windows starting" and the appearence of the logon screen, the screen stays black for while. This a known issue with the logitech "unifying" receiver. I'm just trying to find out WHICH of the "security update" is causing this.. Perhaps someone here knows?

I'm not awate of any relationship between these receivers and updates - and to be honest, can't really see why there should be.
The latest Logitech software update appears to be 2010 vintage - perhaps you should check each connected device and see if there are more recent drivers available for them. It may simply be that this device forces detection early in the boot process which would normally be carried out at a later stage - thereby causing this apparent slowdown

What happens if you unplug the device before boot, and plug it in later?

Perhaps there's something in the event logs that will tell us...

Open Event Viewer
click on the Windows logs entry in the left pane to expand it.
Now click on the Application entry - wait while it loads.
Click on 'File' in the menu bar and select Save...
Save the file as Appevt.evtx
Repeat for the System log
then zip both, and upload them.