Wow, and I thought this topic had died a long time ago
The make of the hard disk isn't too important as far as I know. What needs to happen is that you need to load the kernel module for the sata controller, on the motherboard, before you start to install.
Firstly, you need to find out what the sata controller is. This can be done usually by looking in the manual and finding the chipset that the motherboard uses. It is usually something along the lines of a "Broadcom" or "VIA" chipset. If you can't find it or aren't sure, post the exact model of the pressario that you have and i'll have a hunt for it.
Once you know the chipset, you can look for the chipset driver. The module can then be loaded during the red hat install. I seem to remember something about being able to load modules during the install , ( I have never really used Red Hat but I'll grab a spare pc and run an install to check after breakfast) , so it should be easy once you have the right module.