Thanks Farnz. I've looked at every file that I can open on the installation CD but the only reference I can find is to "the serial number on the inside cover of the CD holder". However, it came in a totally clear holder.
The old PC was early 2002 vintage so this version of Elements must be the same era. Are there any free downloads available anywhere now? I only want to do very basic work so don't necessarily need the latest version.
I would prefer Photoshop to any of the other photo manipulation programmes.