cheyenne:Sorry to be thick, should I uninstall first. Originally I had S12 on a disc before I upgraded is it worth doing the transfer wizard?
In the first case I'd try re-downloading and running that - it will probably offer you to do a repair install.
The transfer Content Wizard is for transfering "Extra" content, so I doubt if that will work.
The guy on the other thread seems to have done the same as you - installed a downloaded upgrade to S12 Ultimate over an existing, working instalation of S12 standard/plus. Have a read of that thread and see if you can see any similarities.