You should back up your library whenever you have made changes or additions. If you create or amend filters, output styles or connection files, it is a good idea to back up the entire EndNote directory on occasion. You can save your complete library (the .enl file as well as its associated .Data folder and all of its contents) to a single compressed .enlx file in order to easily back up your library or send a copy to a colleague. Later, you can easily restore (unzip) the compressed library with EndNote.
To save to a compressed library file:
To restore a compressed library file:
To avoid problems with your EndNote library: