I am trying to embed a youtube video in dreamweaver cs4. It's embeding but all I see is a white or grey box and seems to be missing a plugin...How do I get this to work, including the plugin?

I am trying to embed a youtube video using Dreamweaver cs4, but it seems to be missing a plugin. I have a flash on my laptop (pc). How do I get this to work to where it will show because all I keep seeing is a white or grey box when I embed the code. I've seen many videos of people doing it and theirs worked just fine, but mine will not load.