I's been a while, but I got bored today and made some stars. Here's a link, the image is 3200x1800 so I didn't want to link it here.
Now I just have to think of some things to put in front of those stars...
They aren't pdf files, in fact those plugins will work as-is if you put them in the right folder. To change the default program back, right click on any .zip file, go to 'open with' and click on windows explorer.
I seemed to encounter this too, but after it said "Paint.NET encountered an error and needs to close," it didn't close and I went right on pasting and dragging.