I'm having some surprising results upgrading unsupported hardware to Windows 11. Some machines I would expect success on, but I have a lot of "unsupported" systems as well where I would have expected at least a small amount of resistance. Here is breakdown of the unsupported systems:
1 Machine that will never run Win 11 as it is BIOS based, and has no TPM (very old machine. At least 10 years old.)
1 Machine is a 7th Gen mobile i7 making it unsupported, but it does meet all other requirements (TPM, Secure Boot, etc.)
1 Machine is a 6th Gen mobile i7. Like the i7, the CPU is the only technically unsupported item.
1 machine is a 4th Gen desktop i7. Is has a TPM module but it is a 1.2 version, not 2.0.
1 machine is a 3rd Gen i5 (!). Does have a TPM 2.0 module.
I was able to successfully install Windows 11 on each and every one of these systems except the first one (the BIOS based system), without making ANY changes whatsoever. Just took a 100% unmodified Windows image on a thumb drive and do a clean install from it. I was a bit surprised at how easy this was.
My point here is that if you have some old hardware, don't be discouraged. At least give it a try and you may be surprised at the results. A couple of notes:
1) I would suggest making a backup of your current installation so that you can revert back easily.
2) Note that you will need at least a version 1.2 TPM. At least I had that going for me. I equip every machine I've built in the last decade with a TPM.
3) Expect this to work only with a clean install, NOT an upgrade.