Use Internet Explorer to download/install Chrome (or firefox), try youtube on that. That'll tell you if it's the web browser/addons at fault.
(this is the only correct use for IE by the way )

Try similar videos - vimeo, news.com.au, liveleak, etc - also happen?

If problem persists try downloading installing latest video drivers & Uninstall/reinstall flash. Google how to find how/what if you need to.

If problem still persists then worst case it might be a warranty job but if it plays other vids ok then it's unlikely..