Laptop not recognized by Resource CD

I just recently reformatted/reinstalled XP on my Inspiron E1505 (which, according to my service tag, is actually a 6400?), and upon trying to use the Resource CD, I found none of the drivers would install. One notification told me that the system is not a recognized Dell device. Why would that happen?

Without that CD (and the reason I can't use it), I'm kind of dead in the water. I have another laptop, but I kind of had plans for the old lappy.

I should note that I have done this before, and never had a problem- aside from having to manually track down a few wayward drivers. Any suggestions would be appreciated.