2007 White Macbook unable to watch online videos

Everytime I try and watch a video online whether it be a youtube clip or a tv show/movie, the video becomes choppy and the sound starts to cut in and out. After about 2 minutes of this, the screen becomes greyish and tells me that I must restart my computer. Even if I allow the video to load all the way, this will still happen. While this is all going on, my computer is super super hot.

Any suggestions?

Definitely sounds like overheating to me - the white Macbook's heatsink is rather small compared to most other laptops using that same CPU. It's therefore more sensitive to dust buildup...sounds like your heatsink is fairly clogged.

The best thing to do is remove the heatsink completely, re-apply thermal grease, clean the heatsink/fan assembly and re-assemble it all. However, that's pretty involved - second best is to aim a can of air duster in the vent under the screen and give it a good blast.