How do I change video formats so that they will open on media player?

at the moment they will only open on quicktime but I need to link 5 of them together for youtube??How do I change video formats so that they will open on media player?FormatFactory is a free programme that can convert multiple different audio, video, and picture formats.



You can download it from the following website.



You'll be able to import your video files into Windows Movie Maker, and join them in that.



Windows Movie Maker supports the following file types:



Audio files: .aif, .aifc, .aiff .asf, .au, .mp2, .mp3, .mpa, .snd, .wav, and .wma

Picture files: .bmp, .dib, .emf, .gif, .jfif, .jpe, .jpeg, .jpg, .png, .tif, .tiff, and .wmf

Video files: .asf, .avi, .m1v, .mp2, .mp2v, .mpe, .mpeg, .mpg, .mpv2, .wm, and .wmv
How do I change video formats so that they will open on media player?
What formatis the file in?