No Audio in Movie Maker?

Hi, I've just spent the last hour trying to convert my .MOV files to .WMVs in the hopes that the audio would work. Sadly, I was wrong, so I came here to look for help. I have absolutely no idea why, this has never happened before, but I cannot hear audio when I try to play my files on movie maker. The video shows up just fine, but not the audio. Could someone please help me? This is really odd.