I have a Lenovo IdeaCentre with an Intel Core i5-6400 Processor.

It has a frequency of 2.7 GHz, it supports 64-bit.

It has 4 cores and 4 threads (whatever those are).

The system has TPM 2.0 enabled.

PC Health checkup tells me my CPU is not okay for Windows 11. Why not? It meets the speed and core requirements. I don't get it.

The current CPU socket type is FCLGA1151.

If I can't upgrade with my current CPU, I wonder if could get a different CPU for the same motherboard and socket or maybe replace the mainboard and CPU altogether. Getting a brand-new PC with the same amount of memory, and SSD drive compatibility, and having a DVD/RW drive and all the USB ports I have would be really expensive. I have a good system, and I'd like to keep most of it without breaking the bank.

Any thoughts?