How Can I Update New Windows 8 PC Delivered with User Account Control decisions/approvals based on 11/2013 Expired Certificates

Yes, that was the link to the item I remembered! Thank you.
FYI, I wanted to create a Restore Point tonight, and UAC required me to approve the changes based on cert that showed   Valid from:  April 9, 2012;     Valid to:   July 9, 2013.  
Issuer: 
CN = Microsoft Windows Production PCA 2011
O = Microsoft Corporation
L = Redmond
S = Washington
C = US
There is more to the issue than merely the hyperlink that you supplied, so I cannot mark yours as The Answer to everything, yet.  I expect to download and install as indicated, and to report results here, tomorrow, after I can catch my 40+ winks. But this gets me on the road, and I thank you.

At this late date, after all the Optional as well as the Important/Critical patches by Microsoft® to Windows® 8 through yesterdays date, Sept. 16, were installed, the old Cert that expired 11/9/2013 is still asserted by Windows UAC when opening e.g., Windows Task Manager, and almost anything else. Except,  I have not installed the Optional Microsoft Silverlight, but I see no reason to think that would cause this problem. Even to install the monthly 2nd Tuesday patches, UAC asserts the same, expired, Certificate.  So, there is good reason to question whether this Windows 8 is valid. 
   I'm just saying …

Yes, I recognized that this was/is a Micro$oft problem, and I called them about it during my 90days warranty period for telephone support, and spent the obloigatory several hours on the phone, explaining the issue over and over, to successive levels ot expertss; ultimately, there was no ability nor any willingness to correct these expired certificates. The all-too-frequently encountered, virtual help, not real help;. a run-around.  So, I thought there might be a good chance that the updating method described in the link that (was it posted by you?) to which A. Binch was kind enough to lead me, might resolve the issue. However, not really.   
A test late on Monday of UAC by opening the Ststem Restore dialog, stimulated a UAC box that referenced the same old cert that expired on July 9, 2013.  THus it appears that, however many updates for certs the download pack might bring, this cert ws not affected. So, what next? Well, M$ telephone support stalled me off long enough, and now my Windows 8 is out of the 990-days period for warranty service.  I could subscribe to a year of telephone support, for - what? -maybe $199.00, but I don't know why I should believe that the money would buy me the right certificates, nobody would promise that. I am just stuck for the time being.  I wish I had a beter understanding of certificates. The M$ page on certs in Windows 8 Help & Support is veryy superficial, and vague. But I cannot really afford, either, to buyf he training course(s) that would help me work it out.

Hello, AVG Folks,
   I am a paid, licensed user of AVG IS 2014. I saw an AVG Expert's suggestion in the Community somewhere, in which he presented an answer to someone, giving clear and exact instructions for going to the "right place" on microsoft.com I think it was, and spelling out the URL from which to download a pack of updated certificates for Windows® 7 or maybe Vista or XP. It was after 3 AM last night, and my poor tired brain just cannot get me back to that topic in these discussions. 
   My almost-new HP Pavilion was delivered with Windows 8 nd Win 8 has been regularly updated since it was unboxed by this user. The UAC is set to default and it makes me approve of nearly every settings change and of course, of installing updates and new programs. The details in the UAC dialogbox does offer the user an option to review the security Certificate for the installer and then to approve going on with the changes.  Most of the time, these certificates were issued to Microsoft by Verisign (often, by Microsoft Certification Authority).
    One of three certs is usually selected by Windows 8 UAC for each change, as if UAC thinks it guarantees the installing program is safe to install. The problem is, the Certs offered by UAC are expired! and Microsoft's Help info on security certificates tells me not to trust a certificate when installing a change, unless the cert. looks in order with current validity dates. THe dates of these are like, July 9, November 24, and December 2, 2013. All expired months ago, and Microsoft® puts out updates every month on Patch Tuesday but it never has replaced tose certs with valid certs. I don't know why not. I recall that until the last year or two, there was a monthly package of updated certificates on Patch Tuesdays, when I was running Windows XP SP3 and/or Vista.  I have installed all the Important updates that Windows Update offered me, this week, but the cert I was offered at last change or update still had the same expired date.
     Might AVG resident experts be able to give me a link to the discussion showing how to download updates for these UAC certificates for Windows 8? That will be much appreciated. (Assuming Miro$oft still produces updated certificates appropriately this year.)  Please advise.

By any chance was this the link (https://support.avg.com/answers?id=906b0000000D4paAAC) that you were referring to.

Yes, that was the link to the item I remembered! Thank you.
FYI, I wanted to create a Restore Point tonight, and UAC required me to approve the changes based on cert that showed   Valid from:  April 9, 2012;     Valid to:   July 9, 2013.  
Issuer: 
CN = Microsoft Windows Production PCA 2011
O = Microsoft Corporation
L = Redmond
S = Washington
C = US
There is more to the issue than merely the hyperlink that you supplied, so I cannot mark yours as The Answer to everything, yet.  I expect to download and install as indicated, and to report results here, tomorrow, after I can catch my 40+ winks. But this gets me on the road, and I thank you.

Yes, thank you. I was just wishing…   It seems to me, to be a worthwhile enhancement, and so many of the other forums in the industry DO provide that facility for the original poster when logged in. Ah, well …