I just pulled the laptop out of the closet and ran PC Health Check. It found incompatibility because I don't have Secure Boot enabled because legacy BIOS is enabled. I haven't been able to get into the BIOS on this laptop and change it back to UEFI for a couple years now. Last year, I took it apart, cut component connections, resoldered connections and still could not get it to reset. I turn it on today and after entering 2 passwords, the BIOS screen pops up. Why couldn't this have happened 2 years ago? I changed the BIOS to UEFI and restarted the computer which would not boot. I reinstalled Windows 10 and it now boots up. Then I ran PC Health Check again which now shows me that my processor is incompatible. This has got to be one of the clumsiest tools I have used.
Did you check the list of needed components? Do you have all of them including TPM-2?
On my pc, I don't have secure boot or the TPM module.
My laptop doesn't have TPM and the processor is incompatible.
Whilst my CPU is meant to support it, I'm in no rush, if it isn't supported, I will just stick with windows 10 until I eventually replace this laptop and I had already started investigation.
I kept XP Pro for many years after support ended because of the programs I had installed programs that simply wouldn't have worked on win10 and I had no intention of purchasing a slew of programs just to get win10.
For me this is little less of a problem and there is some way to go yet before support for win10 is withdrawn, yes it might be nice, but it certainly isn't what I would consider an immediate necessity.
Next step for me is to run the WindowsPCHealthCheckSetup.msi check.