wmv into iMovie

Good, that was easy The harder thing to do but technically better if it worked would have been to check the codecs of the video. Codecs are what are used to encode the separate components in movie files. You might have found that what was inside the wmv was using mp4 video and AAC/mp4-audio codes and all it needed was repackaging into a mp4 movie package. I remember doing this with .wma many years ago. It was really mp3 in a wma package and frankly all I ended up needing to do was change the extension to .mp3 and it worked for most of them.

You will have to convert it to something that isn't so Windows specific. This can start getting very technical an detailed so maybe the easiest thing would be to refer you to the Handbrake app.