Hi @Elton
What supported verification procedure do you recommend for this exact installer and timestamp chain?
The pages that have our hints on verification are here:
so we do recommend an Authenticode check using an updated windows, (via the Code Signing Certificate).
The root certificates are coming with regular Windows updates. The problem here is, if you cannot trust Microsoft Windows (and its roots certificates) itself, then you have other security problems with your system, as Microsoft can install and control all software on your machine.
You can alternatively build up a trust chain via GnuPG as indicated in the wiki page above.
Best Regards,
Bernhard