Since Windows Media Player can play MP4's by installing some CODEC, no conversion is required.
To sniff out what CODEC, go get MEDIAINFO (it's free) at http://download.cnet.com/MediaInfo/3000-2169_4-10413046.html
One of the best French door fridges we've tested
A good-looking fridge with useful features like an auto-filling water pitcher and a temperature-adjustable "FlexZone" drawer. It was a near-flawless performer in our cooling tests.