"I drag my folder"
You drag the folder or the mp3 file? Is the music an mp3 file? Does it otherwise play okay in WMP?
"I downloaded music from frostwire "
There's the tip-off. FW and Limewire are notorious - awash with fake files and malware. You should have used WinMX or eMule instead, recorded streaming audio using audacity or just ripped from a friend or library CD.
"Apparentley my nephew was on my computer and went in and changed a bunch of stuff not knowing what he was doing."
Apparently he wasn't the only one. many functions on a PC are interlinked, so that changing one can change others, but not everything works that way.
Again, are you sure that the file is a valid MP3 file? Is it about 4MB in size?