So that is not unexpected.
However the diagnostic Cd will NOT work, without the installation that was originally on the HDD from Dell
The error you have means that you will have to now proceed to this step and try and recover your data
Follow the guide including using the porgram to burn the ISO image.
The download link for Puppy does not now go to 5.20 Lupo as a new edition has been established.
USE THIS LINK for the Puppy download.
All the other instructions in the guide are the same.
OR you may proceed with the removal of the drive and its connection to another computer as on my previous post