On my Windows XP machine I am getting an application error as follows in the event viewer:

Failed extract of third-party root list from auto update cab at: http://www.download.windowsupdate.com/msdownload/update/v3/static/trustedr/en/authrootstl.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.

This error is attributed to "crypt32". What is it trying to do?


When searching for authroot.stl (the file inside the CAB archive) you’ll find it’s the list of trusted root certificates. For example, this article is among the results.

Windows is trying to update its root certificate storage.

Unfortunately, this file isn’t counter-signed with a timestamp and the signing certificate has expired on April 12, 2018. As such, it is now useless. It’s timestamp indicates it was created on September 22, 2017.

Unless Microsoft renews the file, Windows XP will not receive updates to its root certificates. This isn’t terribly critical, unless one of the trusted Certificate Authorities were to be compromised.



It basically means that WinXp is no longer supported and the certificate is outdated. You will run into all sorts of problems trying to continue using WinXP and you will receive little to none support on those.

Crypt32 itself is a library containing cyrptographic functions used by Windows Crypto API: https://docs.microsoft.com/en-us/windows/desktop/seccrypto/crypt32-dll-versions

If I remember correctly Windows XP did not receive a critical update of crypt32 and some other dll that are required to support newest SHA algorithm. This was the major crushing blow to those tryint to continue using WinXP and older IE.

Could it be that you are trying to get Windows XP / IE 8 to access some modern https webservice by installing updates?

  • I understand why the program failed in its operation. That is not the question. The question is what is the purpose of crypt32? In other words, if it had succeeded with its certificate query, what would it have done? – Tyler Durden Aug 16 '18 at 10:50
  • 1
    @TylerDurden - We would need the source code to the application in order to determine that. crypt32 is a Microsoft cryptography library used for lots of different things, the certificate being used is no longer valid so a certificate error is being thrown. – Ramhound Aug 16 '18 at 13:25

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