Anyone know how to verify? The update was only 15mb and I dont get a Windows Start Button and I can't tell any difference it did a little updating then rebooted optimized updates and started up fine. Downloading ISO now but I'd rather not reinstall as this install is doing spectacular with all the latest tweaks I've put into it. Tried windows key + pause break to verify 8.1 but it still just says Windows 8 Pro. Kernel file says modified 4/13/2013 isn't 8.1 supposed to have reduced memory usage?(must have been from installing nvidia 320.49 yesterday) I think I detect some snappiness but maybe its placebo install effect. You would think to reduce memory usage would mean a new ntoskrnl.dll. Need you os pros to shed some light. Thank you in advance.