Mine is Legacy BIOS too!
As I said before, your machine is not meeting the requirements for windows 11.
It is still possible to get 22523 installed, but that is not supported by MS.
Sorry, it requires specific steps that I'm not going to discuss in this thread.
You can find other information on the web and other forums that may be willing to help you in this game.
Good luck.
I agree 100%.
I came here for help with a legitimate Windows 11 update problem on a machine that meets all the requirements and fortunately did find a solution.
Now, however, this thread has been polluted by those trying to solve it on unsupported hardware making the discussion irrelevant.