Having made videos with Windows 10 video recorder, of my guitar playing, I have two problems:

1.  Videos are grainy and sound is not bad but could be better

2.  Except for one; one of my videos is crisp, excellent, but reversed polarity, left to right.

How can I correct the grainy texture and why was one great, but reversed.

Best result would be like excellent video but in the correct polarity. I selected Movie Maker below and Essentials although these may not be correct

th