CAPI2

I didn't get any updates, so no magic for me.

Sorry to hear that. Considering the change in my situation, the root cause of this is even more misterious.

Keep looking, that date wasn't in that certificate for nothing.

Teerex
Have you received an update confirming your earlier message/screenshot?

No. I reinstalled cleanly 10 days ago, and it seems that the offending certificate is not even present on the system. I'll check on another, older Win 7 installation this weekend.

I also have been inundated with this error since early July and despite my pc performance was not affected at all I didn't give up into trying to find the culprit and today, after leaving the Homegroup, it no longer shows up in the Application log.

What a relief.

I hope this post of mine may help someone.

This is the updated information from Microsoft Support.

Article ID: 2328240 - Last Review: September 20, 2010 - Revision: 2.0

Event ID 4107 or Event ID 11 is logged in the Application log in Windows Vista, in Windows Server 2008, and in later versions of Windows and of Windows Server

On a computer that is running Windows 7 or Windows Server 2008 R2, an error that resembles the following is logged in the Application log: Log Name: Application
Source: Microsoft-Windows-CAPI2
Date: Date and time
Event ID: 4107
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: Computer name
Description:
Failed extract of third-party root list from auto update cab at: <http://www.download.windowsupdate.co...uthrootstl.cab (http://www.download.windowsupdate.co...uthrootstl.cab) > with error: A required certificate is not within its validity period when verifying against the current system clock or the timestamp in the signed file.

Read further -
Event ID 4107 or Event ID 11 is logged in the Application log in Windows Vista, in Windows Server 2008, and in later versions of Windows and of Windows Server

You would have thought they would have included the following in their instructions for 64 bit users:-

LocalSystem:
%windir%\SysWOW64\config\systemprofile\AppData\LocalLow\Microsoft\CryptnetUrlCache\Content
%windir%\SysWOW64\config\systemprofile\AppData\LocalLow\Microsoft\CryptnetUrlCache\MetaData

Problem is now finally resolved and no more errors showing in Event Viewer!