And there isn't. The process has been streamlined the most it could (at least, in the free ways you can do it) but it's still more of a hassle than it should be. At least, in comparison to Linux, where in most cases, you can just do 'pacman -S some-awesome-desktop-environment' and select it from your display manager, find a nice theme online and throw it in a folder. If you want that level of customization on Windows, you'll need to get an entire different shell, which can sometimes forget up your system, and not many updated ones are available.