On 6 Aug 2010, at 13:33, Kassen wrote:
The installation instructions I downloaded say to reconfigure the terminal of a Mac but the Apple people I consulted advised me not to do that. They say reconfiguring the terminal is outside the warrantee and they see it as potentially destroying the computer!
I heard of this before, but it's -to put it bluntly- nonsense. You can't really "destroy a computer" by reconfiguring some files. What can happen is that you get enthusiastic, start experimenting late at night and go too far, making the computer unable to boot. Then you re-install the OS; many tinkering Linux people did that once or twice. The hardware will stay totally fine.
Actually, this is not the case on later Mac models, as the OS controls the fan cooling system. So you can really destroy the Mac by overheating it. I think it may have happened to a MacBook Air here - there were problems with the software in earlier models. Suddenly, it would no more reboot. It happened on a very hot day. Eventually, the motherboard, or something had to be replaced. One can also destroy the Mac by making a poorly written KEXT (kernel extension). It is too slow to let all stuff run as programs, so one can make an extension to the kernel itself, running without the normal kernel checks then. If it sabotages the kernel, then the cooling system may not run properly. I'm not sure this has happened, but it is a theoretical possibility, in fact mentioned on the Darwin-kernel list.