Yeah, unfortunately while it’s very simple to set up compressor levels in a DAW or even in feature-rich players like VLC, I haven’t come across any easy way to blanket apply one to your computer’s output without weirdly looping it through something like Ableton.

It seems like it should be so simple to have in Windows sound settings, but it’s never been an option. Sometimes there’s a toggle for “normalization”, but that gives you no control at all. You at least should be able to set compression ratio, lower threshold (in dB), and upper threshold (in dB).