With Firefox, saving a Youtube video to your hard drive is an absolute doddle. You simply install the appropriate 'add-on' and a couple of clicks will do the job.
So I looked for a suitable add-on for Chrome (via that browser's website) but I was surprised that I couldn't find one. Then it occurred to me that it's (technically) illegal to save Youtube videos to your hard drive, which is why Youtube keeps changing things around to try to block the actions of software which save the videos.
Given that Google own Youtube, and that Chrome is Google's own browser, it's not difficult to work out why there will never be an official add-on for Chrome enabling you to save Youtube videos.
Either change to Firefox
http://www.mozilla.org/en-US/firefox/new/
and install this add-on
https://addons.mozill...be-video-downl-10137/
or use some software which is independent of your choice of browser, such as this:
http://download.cnet....9434.html?tag=mncol;2
Chris