Audio Problems

I usually use iTunes for my music listening needs and it has always been good to me. Well, about a month ago, some file went missing or was corupted causing iTunes not to work(it messed up quicktime, and I couldn't reinstall quicktime, and itunes uses quicktime to run). So, I decided I would see if WMP would play the music...big mistake. It loaded all my songs into the library, and when I started playing them, the instrumental part sounded alright, but then when parts with the singer in it, it was terrible, garbled, just a mess, and it slurred out the instruments, bascially ruined the whole song, everyone on my computer. Now that i have iTunes reinstalled, I try playing it in hopes that it was just WMP, but it still has the same garbled mess going on.

Is there anyway I can fix this?

There's something that has to be changed in the sound properties, but I havn't used a PC for a while, So it'll take me a sec to find out what you have to change.

EDIT: Sigh, I can't remember for the life of me what you need to change. Double click on the sound control in the system tray to open sound properties. Click on file>properties and make sure that there is a checkmark in every box. I believe it may be SW Synth that you have to turn down, put not sure. Just turn down all of the songs menus down one at a time while playing music. You'll figure it out in about 3 min.