Backing up your EndNote library is very important - we recommend keeping several copies in different places.
You can save an EndNote library, including the .enl file, the associated .DATA folder, and all of its contents, to a single compressed file. The compressed file may also be included as an attachment if you wish to send to a copy to someone.
To restore a compressed library file, in EndNote, go to File > Open Library to open the filename.enlx file, which will extract the .ENL file and the .DATA folder to the same folder where the. enlx file is located.
Note: EndNote libraries larger than 4 gigabytes or 65,535 files cannot be compressed with EndNote’s Compressed Library command.