"Before attempting to use the MPIDE to communicate with the uC32, the appropriate USB device driver must be installed." - Do I need to install the driver and where can I find it?
In my experience it does it all automatically, I've never had any driver issues.
As far as I'm aware MPIDE isn't needed any more?, the later Arduino IDE versions cover the chipKIT (and various others) - you just need to install the boards.