Video File Format Mngmnt. App(s)?

[videzyrah]

I was wanting to experiment with trying to put together a track for a short film today using FLStudio with the Fruity video player. However, apparently I couldn't get the .mp4 (or a a .mov) file to open in the Fruityvideo player or in the Windows Movie Maker program either.
Thus I was wondering if there was any freeware or relatively cheap utility out there similar to what dbpoweramp can do for converting music files, but for video files instead. Specifically, getting .mp4 and .mov into either .wmv .avi .mpg or .mpeg

Thanks.