i want to help, i just am not following what the problem is.. you lost your driver disk?
The drivers may not exist. It likely that if the computer is newer then there won't be any XP drivers for it. You can check the Dell website. Is that computer has a Sata HDD drive then you will have to install the Sata drivers before installing Windows XP since Windows XP doesn't have Sata drivers. Even if you do this there will likley be other componets that don't work correctly as well. You will have to look around the internet or give something like Driver Packs a try.