Many reason to freeze videos. The main reasons are 1) slow speed internet connection, 2) Poor graphic cards, 3)Running so many programs at the same time, 4) Some times so many people viewing the video at the same time.
You could have a virus on your computer. Also try shutting down all other internet programs so that your internet can focus on the single youtube video. And trying another video might work
A number of factors could be causing this. The most likely is that your computer simply can not handle the load. In this case, get either a new computer or purchase more RAM and a better graphical processing unit (GPU) for your current one.
If your computer is responsive, and it says buffering it may be that your connection isn't fast enough and you have to wait for the video to download. This is a common problem with streaming video.
It's possible that you have too many programs open on your computer. Try closing any open programs. It that does not work, do a shut down and try opening the video again.
