You can easily stop Microsoft from installing Windows 11 on an eligible machine by simply turning off TPM and Secure Boot in the BIOS/UEFI set up. Then in the search box on the taskbar, type command prompt , then select Run as administrator from the list of options. Select Yes . Next, in the window that appears, type the following commands one at a time, including the spaces as shown. After you type each command, press Enter . Then let each command complete before you type the next command.
net stop bits
net stop wuauserv
ren %systemroot%\softwaredistribution softwaredistribution.bak
ren %systemroot%\system32\catroot2 catroot2.bak
net start bits
net start wuauserv
After all these commands are completed, close the Command Prompt window and restart your computer.
Check for updates again.
You should then get the message that this PC cannot run Windows 11