With my recent upgrade from Win7 to Windows 10, I discovered that Win10 System account loads http.sys to listen on port 80, so I had to temporarily set Apache to listen on port 81.
Has anyone found a reliable mechanism to stop Windows 10 from grabbing port 80? I tried the expedient of disabling http.sys in the registry, but that caused all the printers to not be available. Grrr.
So, for now, I'm using port localhost:81 for my XAMPP development system.