how to encode windows media files

I've been putting a couple of videos up on my website (thanks, iWeb) for the past few months, and now I've got one that five million people want to watch. Problem is, most are PC users, and don't understand the concept of a Quicktime plugin.

I'm wanting to give them the option to download the video as a Windows Media file. How do I go about converting a quicktime movie and encoding it into windows media format?