Shortly after the patchday blog readers reported that the update KB890830 was no longer offered via Windows Update. MSRT reissued and pulled from Windows Update What caused this problem could not be clarified – probably Windows 7 SP1 lacks a corresponding root certificate. So, while the KB890830 Update Certificate was invalid for Windows 7 SP1, all other versions of Windows accepted the MSRT Certificate.

However, the check ended with a root certificate that is not trusted by the trust provider.

The error code stands for CERT_E_UNTRUSTEDROOT, which means that the certificate chain was processed though. In the blog post Windows 7: Update KB890830 (MSRT) drops Error 0x800B0109 I outlined the background for error 0x800B0109. I have also read reports that the tool is being installed again and again. With KB890830 all my installation attempts fail. Already on Patchday there were comments like this:

But this MSRT version from Novemcauses issues in Windows 7 SP1 and Windows Server 2008/R2. The update was also rolled out on Patchday (November 12, 2019) for all Windows versions via Windows Update. The tool is available for all versions of Windows and is rolled out cyclically on patchday as an update to clean the systems from malicious software (certain common threats such as Trickbot). Update KB890830 is the 'Windows Malicious Software Removal Tool' (MSRT).

Windows kb890830