Return to the Sketch > Import Library menu. You should now see the library at the bottom of the drop-down menu. It is ready to be
used in your sketch. The zip file will have been expanded in the libraries folder in your Arduino sketches directory. NB: the Library will
be available to use in sketches, but examples for the library will not be exposed in the File > Examples until after the IDE has restarted.
Those two are the most common approaches. MAC and Linux systems can be handled likewise. The manual installation to be
introduced below as an alternative may be seldom used and users with no needs may skip it.
Manual installation
To install the library, first quit the Arduino application. Then uncompress the ZIP file containing the library. For example, if you're
installing a library called
"ArduinoParty", uncompress ArduinoParty.zip. It should contain a folder calledArduinoParty, with files like ArduinoParty.cpp and
ArduinoParty.h inside. (If the .cpp and .h files aren't in a folder, you'll need to create one. In this case, you'd make a folder called
"ArduinoParty" and move into it all the files that were in the ZIP file, like ArduinoParty.cpp and ArduinoParty.h.)
Drag the ArduinoParty folder into this folder (your libraries folder). Under Windows, it will likely be called "My
Documents\Arduino\libraries". For Mac users, it will likely be called "Documents/Arduino/libraries". On Linux, it will be the "libraries"
folder in your sketchbook.