When the bootloader is displaying a message saying it is waiting for a reset, connect the MCLR pin to 0V momentarily and it should then reset the PIC and bootload the new program.
I have connect the MCLR PINT TO 0V, but it still don't work.
I'm using the Max1672 switching regulator, and it has a soft on pin, so I must press the ON button on my keypad for the power to go through to my PIC.
I have done this and then momentarily connect MCLR to GND, but still no luck?

Any idea what else I can try?