I've checked through the entire list of .inc files on my computer. It took ages as there are a lot and the number of header files for PICs were very small, just the odd one here and there from various projects on my computer. There is no folder on my computer with an exhaustive list of header files for every single microcontroller. I'm sure there must be a place to download them as and when I need them but I cant find anything on the microchip website