Don´t know what´s wrong at your end. Server is working. Little Checklist as hint: Installed version of OS? Regionsettings to your location Timesettings (sync with internet time) Firewall (disable for testing) Installed any "offline activator" watermark remover or else ditchy stuff? You´re absolutely correct, deactivating WMC doesn´t alter value for ProductName and VersionID in registry, it seems . One reboot for deactivation, reactivation works imminently.
At least you can try to uninstall key via: Code: slmgr /upk then try installing GVLK again, use the first one from your link for pro-version.