HD Install :: edit menu.lst after frugal installation

Hi.. i have quite the same problem.. i've done a frugal hd install, i'm using lilo as bootloader and i need to edit lilo.conf to add the "nodhcp" commant to the append line... i've succesfully edited the file /cdrom/boot/lilo.conf, but when i try to confirm it with

lilo -C /cdrom/boot/lilo.conf

it replies

Fatal: creat /boot/map~: Read-only file system

perhaps i should add some more parameters to the lilo command above?

sorry i understand it maybe a n00b question.. but.. in fact i am a linux n00b