NOTE: Your EndNote Library file must be saved on your computer's hard drive--that is, you cannot save your EndNote Library file in cloud storage (e.g., Dropbox, OneDrive) or on a flash drive--or your library may get corrupted.
If you need to use your EndNote Library on another computer, you can use the EndNote Online backup or sync your library to another instance of the Desktop software.
On a Windows PC, go to the File menu in the EndNote software and select New...
Rename the library file and choose a save location. The default options are usually fine.
All of your library's associated files (such as PDF attachments) will save in the same folder location.
The best practice is to have only one library file instead of a separate library file for each project. This way, all of the references you have imported into EndNote will be available for you to access and reuse in the future. Instead of organizing using different libraries, you can organize your projects using Groups.