It is very important to back up your EndNote library as a corrupted library could negatively impact the timely completion of an essay or dissertation. For backups it is recommended to use File > Compressed Library. A Compressed Library is a zip file which should be held in reserve in case errors in your library can't be reversed; it shouldn't be opened if it is not necessary. Save a compressed file to several locations - for example a thumb drive or external hard drive in case your device crashes or is stolen. It is not recommended that you save Libraries (normal or compressed) to cloud-based locations such as Dropbox or iCloud. These services have been known to corrupt the code underlying the program data.
Each time you save a new Compressed Library with your latest uploads, delete the previously compressed library.
Each EndNote library consists of two parts:
| File | Type | Function | Location |
| Library | .enl | Contains all your EndNote references | in the same folder as the .data Library file |
| Data folder | .data | Contains supporting information such as terms and group structures. It may also contain your attached files and images | in the same folder as the .enl Library file |
It is important to retain both of these parts of your library. You can reconstruct an EndNote library from just the Library (.enl) file, however, your organisation and attached files will be lost if you delete the .data folder.
You may also back up your library by using EndNote's File > Save a Copy. However using this function creates a full copy of your library - meaning that you would have 2 versions of it, which can create confusion as to which is the master or working library. It is therefore recommended that the Compressed Library function is used for back ups.