According to numerous reports, Windows 10 updates KB5000842 and KB5001330 cause annoying performance bugs for games running in windowed modes. Per Microsoft’s patch notes, “a small subset of users have reported lower than expected performance in games after installing KB5000842 or later updates. Most users affected by this issue are running games full screen or borderless windowed modes and using two or more monitors.”
If you’ve noticed stuttering or crummy frame rates suddenly affecting your games, this is likely why. Fortunately, it’s easy to fix.
In the past, we’d normally suggest users uninstall these updates to fix the issue and recommend other users delay installing them to prevent the performance drawbacks from affecting their PCs. However, Microsoft is pushing an official fix via Windows 10’s new Known Issue Rollback feature that will take care of it for you.
Known Issue Rollback (KIR) is a relatively new feature that can “quickly revert a single, targeted fix to a previously released behaviour if a critical regression is discovered.” Basically, KIR can disable buggy parts of a Windows update for you automatically, rather than forcing the users to uninstall the entire update. That way, Microsoft can fix unforeseen post-patch bugs — like the recent gaming performance issues — and users can retain important security updates.
In fact, Unlike normal Windows updates, the KIR process happens in the background automatically. Microsoft has used KIR numerous times in the past to prevent bugs from spreading once they’re identified.
If you installed KB5000842 and KB5001330, you just need to wait for the fix to roll out to you. Microsoft says it could take up to 24 hours for KIR to fix the bug happen, and suggests rebooting your PC if you don’t notice any changes. You can check to see if KIR is installed on your system by launching the Registry Editor and checking to see if you have the following key:
If not, sit tight. Once the offending updates are removed, your PC’s gaming performance should return to normal.