I'm interested in how you downloaded a video from youtube.
I run Linux/Ubuntu so I just hit F12 to open a terminal, type in "cd Videos" to change to my Videos folder and then type "youtube-dl https://www.youtube.com/watch?v=Jktvh6k0qys" without the quotes
There's a version for windows but it does have some prerequisites like needing Python installed on your system because it's written in Python programming language. Works like a charm though and all the browser plugins were turning to crap. Want you to sign up on their website to be able to download 1080p videos etc.