Well, as I mentioned to the other guy, to disable the onboard video, you're going to have to install a different video card (else, how would your monitor work? )
I'm not familiar with that machine, as I don't have one, but typically, there is a way to disable the modem (and other peripherals) from the main BIOS at startup.
Yeah, you and DUC user skipper have almost identical rigs and exactly the same problems:
check the other thread for other suggestions.