Why my Windows 11 won't do a clean install?

I am trying to perform a clean installation of Windows 11 using a bootable USB drive, but the installation keeps failing at random points with different error codes each time. The setup process either freezes completely, throws a generic Something Went Wrong message, or crashes back to the initial setup screen without any clear explanation of what is causing the failure.

I have already recreated the installation media using both the Media Creation Tool and Rufus, tried different USB ports and drives, and even disabled secure boot temporarily but nothing seems to resolve the issue. Separately, I am also dealing with Windows Update repeatedly failing to install the same cumulative update for the second time in a row on another machine, with the update always rolling back after reaching around 70 percent. Has anyone else encountered these specific problems and found a reliable fix that does not involve replacing hardware or performing endless troubleshooting loops? Any guidance would be greatly appreciated.