Mayhap this will help, Mayhap not.. Good luck though!
Mayhap this will help you, mayhap not... Bear in mind, I haven't received my 7700 yet, so I don't know the exact keystrokes to enter the BIOS (anyday now though!).
Attach your USB floppy to your computer before you boot. Once it starts to POST, hit the [F2] key, or [F10] key, whichever one takes you into the BIOS. Look for the section that will "Enable" USB ports upon boot. With your Floppy attached, it should recognize that a USB device is present.
insure you have the drivers from your SATA or RAID array downloaded onto a floppy disk, prior to doing this. If you don't have a SATA drive or a RAID configuration, see second note below.
once you have all of this, Boot from your XP CD, and once the installation begins, look for the prompt " Press [F8] to load raid drivers
" That may not be the exact message, but it is something to that effect. SOrry, am running off of memory here. Once you hit the [F8] key, insert the floppy with your drivers on it into the floppy drive and direct the loading prompt to your Floppy drive (Usually A:\ <driver name>).
Once you load the third party drivers for your hard drive setup, the installation should detect your hard drives.
DELL OEM installation disks are a finicky lot. Naturally, they are made for DELL machines. It may not work correctly without changing the DELL config file located on the installation disk. I have had to do that a few times with various installation CD's from DELL, to be able to use that software on non-DELL systems.
I hope this information helps. If you need anything else, feel free to PM me. I'll help if I can.