I assume you mean from Youtube?
Go get FireFox if you don't already have it: FireFox.com
After FireFox is installed, Install Video Downloadhelper:
https://addons.mozilla.org/en-US/fir...dl-mostpopular
And install.
Go to Youtube to the Video you want and you'll see the 3 circle Video Downloadhelper Icon
Click and download where you can find it.
For a Video Player I'm a fan of VLC:
VideoLAN - Official page for VLC media player, the Open Source video framework!
That's it
