Where can I find the Peripheral Library for MPLAB® XC8/16/32?
The Peripheral Libraries for compilers can be downloaded from Microchip's "MPLAB^^®^^ XC Compilers" webpage, under Downloads > Peripheral Libraries (PLIBS) > Legacy Peripheral Libraries.
The location for the Peripheral Library must be manually selected during the installation process.
(On a normal installation process - C:/ProgramFiles(x86)/Microchip/xc16/vX.XX)