WMP12, W7.
I am very happy with WMP and don't want to change as it syncs with all my equipment beautifully.
However, it is now including ALL music files that are on my pcs such as Windows sounds - the exclamation sound, log on, log off, notifier etc.
I'm sure there is a way to exclude 'music' less than 1 minute from the library or other way to exclude these sounds but simply can't find how to do it.
Sounds like you've probably added the whole C drive to your library..
Click organize > manage libraries > music and make sure you've only got your music folders listed.