Thanks for such a quick reply,
I did copy the entire library directory to the other machine, but Calibre doesn't appear to be reading the file metadata.db correctly. The copy on the new machine doesn't show the Covers and metadata I added into the metadata on the other machine.
I've even tried re-adding all the files, but it still won't show my edits from the other machine.
Is the edited metadata not being stored in the book directory on the first machine? (Eg. I've messed my settings up some how?)
I don't know if it makes any difference if I'm switching from a Windows 7 to a Windows XP machine? (XP being the one I'm trying to copy to)
What is stored in the Application Data in Windows 7 and XP? Am I missing something from there when I copy to the other machine?