I want to burn a Mega168
Here are the relevant fuses, as shown in AVRStudio:
No , I think if you have a isp programmer , I don`t think you can brick it.
Nope, with just an ISP programmer, you can 'brick' an ATmega. The easiest way is choosing an impossible oscillator setting or disabling SPI. (Notice above how AVRStudio can't alter this value in ISP mode.)
I ask in avrfreaks and all answers were that I only can reset this fuse using a Higth Voltage programmer.
Conveniently, the AVR-Dragon IS a high voltage programmer.