Update installed automatically in the last 3 days (on 2 machines). Windows Update now shows as requiring a manual check for updates on 1 machine. Other PC shows "Never" and "Never" for any updates after stopping and starting wusus service. Trying to connect to Windows Update service, get error 8024402F on machines. Update troubleshooter fails to download. Cannot download ANY updates now manually. Even trying a SP download the validation of Windows will not run either using the "auto" verification or by doing a "manual" validation where the browser will not even go to a Windows Update page to validate (IE cannot display the webpage). Also get the same cannot display the webpage going to windowsupdate.microsoft.com which suggests this update has wider implications. No rollback possible as it's an exclusive update. No way of manually connecting to the update service to try to recover as Windows validation fails! Checking the System page, still shows Windows as activated and genuine. Windows 7 Enterprise x64. Win 7 SP1 with all updates installed on both machines up to this KB article. Previous updates installed May 11 including KB2534366, 890830, 2529073 as well as Office updates.