Just did a clean install of Windows. Went to Creators Update, which I didn't have before.
Installed Laragon, and Port 80 is blocked by PID 4 (System). No IIS, no SQL services, no Web Services running at all.
Further, if I change Laragon's ports, all my sites give a weird-looking 404 Not Found error.
I've Googled for two days straight and nothing works.