Since you did not post an exact model number I am going to have to make some assumptions. That chipset goes back about 7 years ago and does not support a generation 8 or newer CPU, which is required to be supported by Windows 11. So your choices are either download the Windows 11 media creation tool here and install Windows 11 on your current system (that method of installation bypasses the CPU check). Or choice 2 is replace your current system with a newer system that is supported by Windows 11.

Keep in mind that you need Secure Boot and TPM  enabled in the BIOS. With the above install method you only need TPM 1.2 or in the BIOS it may be classified as PTT.

I would ask that you also post the model number of your system here in the forum.

@kulli123 

Download Win 11 iso and

use rufus-3.18 with the bypass of Windows 11 restrictions for in-place upgrades

tpm and bios ok; only cpu should changed

replace for a new system is not possible at the moment and it is not consistent to change pc system every 4 years (the pc is 5 years young and its not my fault that the chipset is too old in dell computers)

probably i use win10 further too end of life yet ....