It's probably the print the screen and paste into Paint that's creating the blurry image. The print screen creates a screen capture that's probably only 96 or 72 dpi (depending on your system). When you paste it into Paint, it's already a low-res image. If you do any manipulation to it, the image blurs out.
Instead of doing the screen capture, try saving your render as a Paint acceptable file format. Open the file in Paint and then manipulate as needed.
That might take care of the blur problem.
Looks cool.
