He downloaded the latest: VC_redist.x64.exe for 2022. Version 14.38.33135.0. Signature date: three weeks ago.

This is the most common error. It happens because you already have a newer version of the Redistributable installed (perhaps via Windows Update or a game installer like Steam), and the installer you downloaded is trying to install an older version on top of it.

The terminal closed. The monitors returned to normal. Event Viewer showed no trace of ID 4789.

Same error.

Note: The Visual Studio 2022 Redistributable is backward compatible with programs built for Visual Studio 2015, 2017, and 2019.