Hankyknot,
A fresh clean installation of XP provides a 30-day grace period during which you can defer activation.
The purpose of the grace period is for you to have an opportunity to install the drivers for your hardware and your software to ensure that they function properly before you commit to the installation and license by activating it.
A good clean installation of XP does not have any trouble displaying the activation screens. I would suspect that the orginal problem may be hardware based, and would also seem to not have been corrected, and this hardware problem is still affecting the integrity of your clean XP installation as it did with the previous XP installation.
I'd start with a good memory test, like this one from Microsoft:
http://oca.microsoft.com/en/windiag.asp
For great advice on all topics XP, visit http://www.annoyances.org/exec/forum/winxp