Missing drivers

Hello
I have Dell Latitude with no floppy drive and a Toshiba external CDROM drive. I am trying to install a new copy of Windows XP on the formatted hard drive. When I insert the disk it asks me if I want to boot from the hard drive or installation disk, I select disk, then it asks if I want to "Start from the Windows CD" or "start with CD support" or "no support", I chose "Start from windows CD". It then does a PCI Bus scan and then gives me this message: "Device driver not found "OEMCD001" No valid CDROM device drivers selected" The Windows XP Setup files were not found. It then goes to the A:\>.
What's the problem and how do I solve it? Thanks