If you want to turn it into just a server you could use something like maslite (http://www.serverelements.com/) it runs of a floppy disk/cd/usb pen drive (depending on whiuch version you get) and would allow you to access files directly on your hdd via ftp or http, although the downside to this is that it runs outside of windows, so you would have to remove windows. If you wanted to keep windows you could simple share the folder with all your mp3's in, as that is what i currentyl do.