When you access the 'aurorun' of the SS7.40 CD there is an option under the "Software" tab, named "Create Driver Diskettes". Select that option and follow it's instructions. It will build the required floppy. Then when you get ready to install RH, boot the system from the 1st RH CD, and at the prompt, type 'linux dd'. Put the floppy you built, into the floppy drive and press enter. The installation process will prompt you from there.
JL