How to copy iTunes Library from one user profile to another?
Solution 1:
The easist way would be to copy the files in "C:\Users\thomas\Music\iTunes" to the same folder in your new user account. This should link everything back to the external drive. The files are:
.iTunes Preferences.plist
iTunes Library Extras.itdb
iTunes Library Genius.itdb
iTunes Library.itl
iTunes Music Library.xml