How to set and change Configuration Bits programmatically?

[tumbleweed]

You may not be able to do what you want if any of the code protection bits are set...

Note: Code protection bits may only be written to a ‘0’ from a ‘1’ state. 
It is not possible to write a ‘1’ to a bit in the ‘0’ state. 
Code protection bits are only set to ‘1’ by a full Chip Erase or Block Erase function. 
The full Chip Erase and Block Erase functions can only be initiated via ICSP or an
external programmer.

Since you can brick the device if you get the config bits incorrect (ie wrong osc type) I like to have the bootloader just ignore reprogramming the config bytes.

[mikebar]

You may not be able to do what you want if any of the code protection bits are set...

Note: Code protection bits may only be written to a ‘0’ from a ‘1’ state. 
It is not possible to write a ‘1’ to a bit in the ‘0’ state. 
Code protection bits are only set to ‘1’ by a full Chip Erase or Block Erase function. 
The full Chip Erase and Block Erase functions can only be initiated via ICSP or an
external programmer.

Since you can brick the device if you get the config bits incorrect (ie wrong osc type) I like to have the bootloader just ignore reprogramming the config bytes.

Thank you for your answer.
What you say is True.
In the current scenario, all the CODE PROTECTION bits are set. I don't want to deal with that.
What I'm trying to do, is to change the bits WRTC (Configuration Register Write Protection bit) and WRTB (Boot Block Write Protection bit) that are currently set, and I wish to revert to "not protected".

Do you think it is possible?

Unfortunately yesterday my old ICD2 decided to not work anymore. So, I've to wait for a new (and expensive ICD3), but it will be here in 5 or 6 days. So I've mandatory to wait for my own tests...

Regards.

[tumbleweed]

I'm not sure, but I think it treats all of the CPn, WRTn, and EBTRn as "code protection bits" so if they're set to 0 I don't think you'll be able to change them.

According to the datasheet the WRTC Configuration protect bit can only be written via ICSP or an external programmer.