PSA: Mainstream support for Windows 8.1 has ended
Of course, Windows 8.1 devices are still eligible for extended support, which provides security fixes for the OS and will last until January 10, 2023. Unfortunately, if anything ends up breaking in the OS from now on, Microsoft is no longer obligated to fix it.
If you are still running Windows 8.1 and would like to upgrade to Windows 10 for free, remember that the free Windows 10 upgrade offer for users relying on assistive technologies has been extended to January 16. This free upgrade path is frequently seen as a loophole for those who missed the July 29, 2016 deadline for the official free upgrade to Windows 10.