Apparently after the update is installed the operating system cannot validate the fix and causes infinite reboot loop PCs and servers, according to the Microsoft Support forums: As a possible temporary fix, one of the users in the forum recommended setting Windows as the default boot loader in the BIOS as the GRUB boot loader seems to be getting in the way. This is an issue affecting a small number of computers and Microsoft has yet to comment on a permanent fix. If you still haven’t installed the update, it would be wise to go to Windows Update, right-click the update KB3033929, and click “Hide this update” option. Also, try to uninstall the update (if you can). Go to Windows Update in Control Panel, then click View update history, click the Installed Updates link, look for KB3033929, select and right-click it, and choose Uninstall. Source Microsoft Support forums via Neowin All content on this site is provided with no warranties, express or implied. Use any information at your own risk. Always backup of your device and files before making any changes. Privacy policy info.