Marf213,
You will be able to use the Dell OS Reinstallation CD XP Home SP2 for both computers.
The Dell CDs look for specific data embedded in the motherboard BIOS to verify that they are being installed on Dell computers. Because of this, you will not be required to enter a Product Key during installation. After Setup is complete you will activate and validate normally.
For faster and better results, use Dell PC Restore by Symantec instead of working thru the drudgery of a full installation. Restart your Dell, and after the Dell logo look for the blue bar with
www.dell.com at the top of the screen, it will be there for exactly two seconds. When you see the blue bar, press CTRL + F11 to enter the Dell PC Restore utility. Be sure to offload any data you wat to save before running this utility because all user data from the C: drive is destroyed as the computer is reimaged back to the "ot-of-the-box" condition.
For great advice on all topics XP, visit http://www.annoyances.org/exec/forum/winxp