Tomorrow's Update Tuesday will be the last one for Win8.1 -- there will be no further support & there is no extended support option. Win7's extended support also ends tomorrow for those businesses that paid as well as those who installed the hack to receive security-only updates since Win7 reached EOL [End Of Life]. For Win10 we've got until October 14, 2025, though Microsoft will probably offer an extended support plan. We'll have to wait & see if someone comes up with a hack for that, though Win11's so similar, and there are so many hacks to get it working on unsupported hardware, that no one may feel the need.
If you need any help feeling old, that time just flew by, Win7 was official in July 2009 [I was a beta tester], Win8 in August 2012, & Win 8.1 in August 2013, a year later.