I had the same problem where adding media into the directorys was not refreshing -- and removing and readding the directory did not help: In windows 8 if you click on the library it will open with the music app.
Change what opens the file to windows media player from the list, right click on the song.
I know with older versions of media player you could force a refresh of the library but i can't seem to find it in 12.
Any help would be great Thanks You should be able to manage your folders under the "organize" tab and make sure your Media Player is set to auto-refresh.
By default, the music files in your My Music folder are added to your library.
If this check box is selected and you perform any of the following actions, the Player tries to update any missing media information in your music files by sending data about the files to a database operated by Windows Media.com: For example, if you have music files that contain the artist name but not the album name, the Player adds the album name to the file after retrieving the information from the database.
To let the Player rename music files in another folder, you can specify the folder to which files are ripped by using the Rip Music tab.