If you put the wav files on a cd (burn it as an audio cd, not a data cd) then media player will just rip them all or any of them you choose. Open media player and click on the RIP tab.
If you go to Tools - Options - Rip you can tell it what format you want (mp3 or wma) and what bitrate you want, up to 320. It's fast and painless......
Only thing is I've never tried to do it with wav files that are just on the hard drive. I've only done it with wav files that I've already burned to cd. But if all you want is conversion to mp3, media player already comes with windows. You dont have to download or buy a seperate program just to convert to mp3. It will convert your favorite cd to mp3 files in just 2 or 3 minutes.
What kind of sound card does yourcomputer have in it?