Github provides a tool that..

[Grizzly]

... gives more information about what prevents the installation of Windows 11.

https://github.com/rcmaehl/WhyNotWin11 (scrolldown to the Download section - Your AV software may complain)

 

[Bastet]

I’m all good apart from the processor which has a yellow question mark.

I would expect that you could change the Boot method to UEFI, turn on Secure Boot (if available) & Disk partition type to GPT to be more compatible.

 

[fdegrove]

Hi,

This tool works great.
All that needed be done in my case was to increase the primary partition to 64GB. For which I needed to backup the recovery partition since the current partition was smaller than 64Gb.
I made an image of the RE partiion using Macrium Reflect and stored on a separate outboard drive.
Then I removed the RE partition using diskpart followed by removing the D volume partition on the same primary disk.
Increased the size of the C (system) partition to 64Gb.
After that I rebooted to Macrium Reflect Recovery environment and restored the RE partition so it now resides just behind the system partition.
After a reboot launch your machine and recreate a new volume on the main drive if you like.

So, that's all it took in my case.

Cheers,