Well, to compile a kernel you have to go to the directory where it's source code is stored. Probably /usr/src/linux
There you have to run make menuconfig to configure you new kernel. It's an easy menu system, toy around a little. To learn how to compile it and things, read the kernel-howto:
But maybe RedHat uses isapnp at boot-time. Look in the /etc/rc.d/rc.x (where x is S,1,2,3,4,5) directories if there are links with the word pnp in them (i don't use RedHat so i don't know their names). and remove those links. Good luck!