How to remove duplicate listings for songs in iTunes

So, new Windows 8.1 PC with my iTunes library stored on an external hard drive.

Installed iTunes and fired it up without issues.

My music is there--but almost every long is listed twice. Info on each song shows it's pointing to the same file, so I don't have duplicate songs, I have duplicate listings.

Any idea how to fix this? Move the library to my internal hard drive?

Thanks in advance...