What’s the best solution for converting Power Point show to video?

I need to add a Power Point show to a website. The show already has a sound track associated with it (it’s a ppsx file). I am thinking it would be best to convert it to video so that it would be more universally playable.
I see lots of products to do this, but I don’t know whether it’s best to purchase one of these specialized products (IMToo, Moyea, etc.) or if there’s a more generic solution. This is something I’ll probably only be doing once or twice.
I am working on a Windows platform, but I have access to a MAC if that opens up better possibilities. I want the result to be platform/browser independent.
Thoughts? Experiences to share?