You need to check supported processors.
None of mine were, so I had to buy a couple of new laptops.
https://www.tomsguide.com/news/these-are-all-the-intel-and-amd-cpus-that-can-run-windows-11
Well, what I’m seeing online CURRENTLY* from refurbishers and such (more as a guide than expecting to purchase several!) is that said refurbishers are moderately commonly putting Win 11 Pro on, say, machines with 6th gen I-series processors — supposedly not supported, but these sellers are saying “no problem”. One fellow says they also do all current updates B4 shipping. Seller has very good ratings / reviews, so I tend to believe him, but, I don’t know the details / are “tricks”** needed for every update to proceed?
*That “Tom’s” article is old (for the computer world.) (And I should talk about “old” - hahaha, considering I still have a DOS 5 machine that still works - as of last month, anyway.)
**Basically consists of turning off the “Trusted Platform Module” detection, apparently?
I recently discovered that the high-end CPU (i7-3820) that I installed Windows 7 Pro on years ago was not qualified for running Windows 7. It never caused problems that I could detect, and would run nicely without crashing until one of the monthly Windows Updates became necessary.