Microsoft have rolled back part of a recent Windows 10 patch which has caused performance problems in games for some people, particularly people with multiple monitors. If your games have been wonky recently, try again now! Folks started reporting performance problems following patches on March 29th and April 13th, and now MS have cut off the problem part. Should be fixed now?
"A small subset of users have reported lower than expected performance in games after installing this update," Microsoft said. "Most users affected by this issue are running games full screen or borderless windowed modes and using two or more monitors."
My two monitors and have experienced wonk since the March update, though computers are such mysteries I hadn't pinned down a specific cause. Some people reported that uninstalling the update fixed the problem, a fix which spread enough that even Nvidia relayed the reports as a possible fix. Now Microsoft have rolled back the specific change that was wonking games.
Microsoft say they're fixing the issue using Known Issue Rollback, a Windows 10 feature which they explain lets them "quickly revert a single, targeted fix to a previously released behavior if a critical regression is discovered." Basically, they can tell your Windows to turn off the bad bit of the patch. They should have happened automatically by now, though I will confess I forced a manual Windows Update check and rebooted my PC too because it's a comforting ritual, y'know?