I think there may be some confusion between "system disk" and "windows XP CD". A system disk or system restoration disk (or even system restore partition) often has everything on it that is needed to put your PC back to the day it was shipped to you. O.S., drivers and extra programs included.
Usually with the Dells, there is simply a Windows XP CD or Vista DVD included. So, for Dells in general, the last comment by BFOJ applies, but I wouldn't call it a System Re-installation disk.
When I think of Dell system disks, they usually have drivers on them for various internal components on them (video, modem, sound).