I know of AUTOMATIC1111's project, but it only really caters for developers. You have to download files, clone it with git, move stuff around... it's a horrible user experience. Not one click.
I found a project called EasyDiffusion, but the installer started dropping a horrifying volume of files on to my disk including masses of useless Python dependencies, including tests which should really not be in there. All of it's just bundled into the installer. And it looks like this stuff was just built by hand and uploaded to GitHub Releases by the author. The UI is also in-browser, not native.
Is there going be a simple, hermetic way to play with this stuff for Windows?