There is no CPU you can install in this model system that will support Windows 11.  If you want to run that operating system with official support, you need a new notebook computer. You CAN bypass the CPU requirements at least for now (Microsoft has publicly stated it may release future updates to Windows 11 that enforce the CPU support requirements, so be prepared if they do;  at that point, you'll lose all updates for Windows 11).    
I ran a PC-Health to prepare for Windows 11 upgrade but it said my system does not meet Windows 11 minimum requirements.  I checked Dell computers tested for upgrade to Windows 11 and the m17 R4 is listed.  It said that 'Secure Boot' was not enabled.  I followed instructions to enable it by changing from Legacy Boot to UEFI, saved, rebooted, F2, and looked at the BOOT section again.  Secure Boot is grayed out and I cannot enable it. Any ideas?   [IMAGE]
M17x R4, Secure boot grayed out - can't enable