What do mean by shutdown?
The Pic24F has a DEEP SLEEP MODE which is as good as turning it off.
You could use an output pin to switch off the power supply.
if we are goning to sleep mode the controller will run in a low power state ie, the oscillator will switch to lprc .
actually i don't want to run in a low power state . i want to off the controller . using any other methods could i do that ?