Some update notes:
"KB3140743 improved the update installation process, as users are now less-likely to receive errors during installing and downloading updates. Problem with installing updates is one of the most common problems that users are facing in Windows 10, so we hope this update will make installing updates ‘more pleasant’ for users.
Along with the update process, Microsoft also improved reliability of startup, installing and configuring Windows for the first time, authentication, resuming from hibernation, shutdown, kernel, Start menu, storage, Windows Hello, display modes, Miracast, AppLocker, Internet Explorer 11, Microsoft Edge browser, network connectivity and discovery, and File Explorer.
Additionally, the update brings some device connectivity, and Cortana improvements, and it fixes issues with favorites to be lost after updates are installed, and with some app crashes.
You can read the full changelog of the cumulative update KB3140743 on Microsoft’s Update History Page
http://windows.microsoft.com/en-us/windows-10/update-history-windows-10"
None of that should really effect RetroArch though... this is getting stupid for updates breaking things. I still say Windows 10 is good... but what the hell.
Edit: If it's one of your lower end laptops I assume it's a combination of something in the update with your hardware not direct fault of the update. We'll find out if others report it. I know RetroArch runs fine for me.