Update your post to include full system hardware specs and OS information.
Make and model keyboard?
What games if any do you play?
Any recent software downloads or updates?
My thought is that something may have reconfigured the keyboard.
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However there are some things that can be immediately done.
Manually download, reinstall, and reconfigure the keyboard drivers directly from the keyboard's manufacturer's website. No third party tools or installers.
Run the built in Windows troubleshooters. The troubleshooters may find and fix something.
Run "dism" and "sfc /scannow"
https://www.windowscentral.com/how-use-dism-command-line-utility-repair-windows-10-image
https://www.lifewire.com/how-to-use-sfc-scannow-to-repair-windows-system-files-2626161
If the above actions do not fix the problem then look in Reliability History/Monitor for any error codes, warnings, or informational events that may have been captured just before or at the time the keyboard stopped working.