Q: Having trouble exporting library

What are you trying to achieve by doing this?  If you are trying to move your library that is a different process.

iTunes: How to move [or copy] your music to a new computer [or another drive] - http://support.apple.com/kb/HT4527

Quick answer if you let iTunes manage your music:  Copy the entire iTunes folder (and in doing so all its subfolders and files) intact to the other drive.  Start iTunes with the option (shift on Windows) key held down and guide it to the new location of the library.

The .xml file is automatically created and already in the iTunes folder.

All I can say is it is definitely there in my iTunes folder, and:

What are the iTunes library files? - http://support.apple.com/kb/HT1660

More on iTunes library files and what they do - http://en.wikipedia.org/wiki/ITunes#Media_management

What are all those iTunes files? - http://www.macworld.com/article/139974/2009/04/itunes_files.html

Image of iTunes folder structure Dec. 2011 - https://discussions.apple.com/message/16923545

see also:

Image of folder structure and explanation of different iTunes versions (turingtest2 post) - https://discussions.apple.com/message/13025536 and https://discussions.apple.com/message/17457605