1. Press the Windows Logo button on keyboard and type Movie Maker.
2. Right-click on Movie Makerand click Open file location.
3. Select Movie Maker shortcut then right-click on it and choose Properties.
4. Click Compatibility tab and then under Compatibility mode tick the checkbox to Run this program in compatibility mode for: once you have checked it, the drop list down option below will be enabled.
5. On the drop list down option, choose Windows 7 and click Apply and OK to save the changes.
Learn that here:
Ironically, the quality issue seems to be a Google tube problem. I have to save the files at a high resolution, otherwise they look like crap after being uploaded. Even previously uploaded videos, that use to look fine now look terrible.