YouTube videos can also be downloaded via Windows command with something called youtube-dl. Never really explored this method, I guess because I always found the Firefox plugin VideoDownloader to be more than an enough for me.
[youtube https://www.youtube.com/watch?v=QCrUGKwc8JA?list=PLWQqrldPh8tLBSTiKIsQwdToUNkl2JrML&w=560&h=315]