In Windows, Standard User privileges often block the communication between the Steam Client and the Game executable. Resident Evil 4 needs permission to "talk" to Steam.

At 100%, Steam silently re-downloaded a single 2MB file. No fanfare. No notification.

Let’s solve them in order of simplicity.

If those fail, proceed to the surgical fixes below.

Launch the game.

This is an advanced trick that forces the game to recognize the specific instance of Steam.exe you are running. It bypasses virtual environment conflicts (like those caused by Windows Sandbox or certain antivirus software).