To view these videos, click on the "VCR Play" button in the middle of the video previews, left and below. If asked, you must also allow ActiveX Controls to view these videos which reside on YouTube.com.
To view the video on the full screen, click on the outline of a square in the bottom right corner. Change back to the previous screen by using the Escape (ESC) button on the keyboard or the inverted square outline in the bottom right corner.
On the bottom of the YouTube screen are additional buttons that you can click to pause the video, adjust the volumn, and even turn on "closed caption" (CC).