I don't know if this helps. I have two tcp dumps (with wireshark).

- The one is with the problem that we are discussing with the invalid certificate. In this tcp dump i see that chrome is downloading "http://www.download.windowsupdate.com/msdownload/update/v3/static/trustedr/en/authrootstl.cab" . So i downloaded it manualy and the results is in the images attached.

- The second tcp dump was done after closing chrome with Ctrl+w, reopened it, visited gmail.com and everything worked as it was supposed to. In this tcpdump there was no visiting in the MS website (windowsupdate.com).