I have a large music library stored as wav files on an external hard drive. All of the files were inported into itunes and kept organized by itunes. One day they are there, the next mostly unable to be located by itunes. All of the songs are still in the original itunes folder location. Is there an easy, quick way to get itunes to find all of these files again? I've load over a thousand cd's into itunes multiple times. I've been coming up with solutions to avoid this process over and over, (for 3 years now) but it seems a new problem always arises. Please help. Oh, I can't drag them in because the album info gets lost when I use that method. Works for lossless, but not WAV.

Use another media player! If iTunes is giving you constant grief switch to a different media player. OR if you wish to keep iTunes, goto file-> add folder to library.
Select the folder that has all the music in it, and do it that way.