It is a good idea to backup your Endnote Library regularly to ensure you do not lose your work. You do this by creating a compressed Endnote Library (.enlx). This incorporates your normal EndNote library file (.enl) and its associated Data folder (.data) into a single file. The compressed EndNote Library has a .enlx extension. You can email this compressed .enlx file to yourself or store it in the cloud e.g. OneDrive or Google Drive.
1. While the Endnote Library is open, select the File menu and click on Compress Library (.enlx)
2. Choose Create and choose whether or not to include File Attachments
3. then choose either All References or a group and click Next.
4. Choose the folder or drive to save the Library to. It will be a file with extension .enlx
5. Use EndNote to open the .enlx file and it will restore (unzip) the library and extract the .enl file and the .data folder to the same folder where the .enlx file is located.