Thought of an additional option.....
Now we are going to work on a suspicion that the IDE controller on the MB has gone bad (Had that happen to me on an IBM box )
and now we are going to disconnect the hard drive from the mother board and plug the CD's into THAT IDE connector on the motherboard.... and ...reconnect both CD's to the cable....
and close the case power on , put in the Dell XP cd and see if we get some action from that.....
garbled even that up....
That would be the procedure.....
"and now we are going to disconnect the hard drive from the mother board and plug the CD's into THAT IDE connector on the motherboard.... and ...reconnect both CD's to the cable...."
That would be the way to go. But the only way to test is with her bootable install cd and that the bios is set to boot from cd, most likely it is if the pc is only a few years old.