Nigel Goodwin ur answer not clearing to me,
i want to ask that
A PIC in the circuit is runing, can i program this PIC in running position??
I mean can inchworm program the PIC with out power off the circuit???
Or it is necessary to turn off the power before program the PIC??
Again, as Nigel said, the answer is "yes", an ICD2 (or any ICSP programmer) can program the PIC while it is powered on, in-circuit.
and just for your information, if you need to ask a specific person a question, if you click on the name of another forum member, you can send them a private message.
Inchworm
Can provide vcc (+5) or be powered by targets +5
In programming mode target does not require its own clock
In debug mode target must have some form of clock (internal or external)
The inchworm does not isolate its 5v supply unlike the microchip icd2.
It can also be powered by the target (many other clones require a 15v supply, unless they have a vpp generator)
The Inchworm was targeted towards the hobby / student market. Its simple to build and low cost.
You can skip the entire lm7805 power supply if you plan on only supplying power from the target (most rs232 clones on ebay work this way)