The safest source is the original RivaTuner disk image archive (e.g., from Guru3D or tech forums).

Once downloaded, configuration is straightforward.

: A powerful wrapper for legacy games that can force modern resolutions and sync settings more reliably than older standalone tools. How to use D3DOverrider! On All Games!

Move to a Permanent Folder: It is best to move the extracted folder to a location like C:\Program Files (x86)\D3DOverrider to avoid accidental deletion. Setting Up D3DOverrider on Windows 10