I found the problem!! :smileyhappy:
P&E micro (and other codewarrior versions) install windrvr6.sys. If this driver is loaded already, the installer fails when executing wdreg_gui.exe -inf "C:\Program Files\Freescale\CodeWarrior for HCS12 V4.7\Drivers\windrvr6.inf" install
SOLUTION:
Uninstall the windrvr6 driver and remove files so that the installer can re-install them
It may also have been possible to disable the P&E micro feature in a custom install??
I'm up and running now anyway! :smileyhappy: