Windows 7: WMP wont play mp3 files just videos..

I noticed my Windows Media Player wont play any mp3 files. I get an error message "Windows Media Player encountered a problem while playing the file" when I try to play a sound file from my WMP library. It will play videos just not mp3 sound files. Also, strangely, it doesnt show in the list of programs in "control panel/programs and features" but it is in my list of pgms in my start menu. How can I get sound to play again in WMP?

You could try going into the Control Panel and click on "Default Programs". Then click on "associate a file type or protocol with a program". Then scroll down the list to .mp3 and see if WMP is the default program. If not, then click on "change program" and you can make so.