Newbie help--Ahhh!!

[Popsicult]

I'm using the free mixpad to make a track for a project I'm doing. There are three tracks to the project, an initial track and two backgrounds that fade in an out. I got it mixed and edited, then saved it as an mp3. When I try to play it in windows media player it only plays loud, hissing static, and also will not burn to a disc. Is there anything I can do to fix this?

Thanks, much appreciated!