Take Flip4Mac WMV Studio Pro for example, what you are getting is a typical example of the capability of the paid for version, that is, the ability to export as WMV comes from the Flip4Mac WMV player plugin which is free for playback of .wmv file but not for export. If you need to export WMV from iMovie, you need to get more expensive version WMV Studio at $49, which allows you to import and export WMV to iMovie. Let me be clear, WMV Studio only allows you to import and export WMV, so if you want to convert your iMovie08 video to other formats like AVI next time, you need to get AVI component.