Oh wait, is this the latest Win 10 update, the really big one? It totally removed my video drivers, so i had to reinstall crt_emudriver and setup VMM again - although i've done that so many times now it's pretty quick. I used V10, with the V12 tools, to keep the interlaced filter. It's far, far slower switching resolutions now.
EDIT: actually, no it didn't remove crt_emudriver, i don't think. It did remove all my video modes, though, and removed EDID emulation, so i had to plug in an LCD. Even then it would only start up in the crushed letterbox mode that normally happens when you don't disable fast startup, even when i kept restarting. Actually, i couldn't get out of that letterbox format. So i just re-installed.