Basically Office Genuine Advantage Notifications (KB949810) fails to update through Windows Update with an error code 80070643 and description "Windows Update encountered an unknown error". I am running Office 2007 Ultimate installed from download. I have restarted OSE service and switched it to "Automatic (lagged)" as described in the troubleshooting article. I have replaced OSE.exe with another version. I have repaired office. I have reinstalled office and in that case I successfully installed all other previous updates except for this one!Short of reinstating my whole computer to its factory state I don't see what else I can do. I tried to search for a standalone installation file for this update but I couldn't find one. Can anyone help?