But these would be different with different CDkeys, which may be what the message is indicating; ie that you need the same CD that was used to do the original install.NOPE! IN FACT, SHE TRIED 2 DIFFERENT XP HOME DISKS WITH THE SAME RESULT
You could try a repair installation. Autorun the WinXP CD and choose new installation from the first screen. After the files have been copied and the pc reboots read the screens carefully to point to the original installation and select to repair it. Just ensure you dont do an ordinary install, which would install a second clean install to the same partition, or delete any partitions.
The whole thing runs like an ordinary installation and will prompt you for the CDkey and other information, but your data files etc should be left intact. I'm not sure if you will need to reactivate but I don't think so.