The Dell 9100 uses a Intel Pentium P4 Desktop processor. You will not be able to use this processor in a New series XPS laptop or 9300/9400 laptop.
The new core duo Dell laptops use a completely different chipset & processor socket.
Try Dell comunity forum & do a search for I8000 upgrades. the later model I8000's supported up to 1ghz processor & an NVidia GeForce 440 go card with the right video drivers. Also support a max of 512 mgs of ram.