desertwind said:
m1v is MPEG-1 Video File. In simple terms m1v is mpg without sound. It will play in just any players.
m1v+mp3 = mpg.
True to the word, like desertwind said.
Now, for your question you can use any alternative like
Ex. 1) Real Alternative
2) QuickTime Alternative or
3) BS Player
If you are sick with these players
you can opt. to re-encode these m1v files to avi using VirtualDub I'm sure you've heard of it!
Just be sure you have the Div-X Codec so it becomes compact or choose any other codec of your choice.
Hint: For all these softwares just Google for them they are absolutely free!!!
You can use WindowsMovie Maker 2 to add the specific background music to the m1v files.