How to download and play videos from youtube - brief tutorial:

Go to youtube.com and find the video you want to download, then copy the video url - look on the right side of the webpage:

Go to savevid.com and paste the video url:

then press “Download” and wait a few seconds. Once the link is processes click the appropriate link to download the video to your computer:

this is the link of the video in high quality.

Once downloaded to your computer you need a player which plays flv files in order to watch the video. One of the really good and free players out there is the VLC player, download it from here:
Get the free VLC video player, install it, and then use it to play the video file you have downloaded from youtube.