You didn't even share which version of Windows you are using. However, my crystal ball tells me that in Windows 10, .NET 4.8 is not something you "download," but activate features from within Control Panel->Programs and Features->Uninstall a Program->Turn Windows Features On or Off.
Hope this helps, and feel free to mark this as The Solution if it solves your problem.
@Christopher-chris - If your installer is failing, then redownload it from your account and try a fresh reboot. If that fails, then, as I pointed out in your "other" thread, I strongly advise you to contact Customer Services.