Some of the videos on there are very low definition due to either their age or the quality of the posters machinery. Just to be sure delete adobe flash player and go only to adobes own site and reload the latest version. This is a good time to do that as earlier versions of flash have been found to be vulnerable recently
The first part (up to the Pixovert logo) is blurred, but that's not surprising as it consists of a Youtube video of a screen capture of a Youtube video!
After that, as long as you watch it in full screen mode, it seems very clear to me.