C&C Tiberian Twilight Registration code problems

Hi,

I upgraded My PC to W8 but because it failed I had to reinstall it from scratch.  Now I want to reinstall tiberian twilight but the registration code is in use.

In the manual I read "If you alread purchased a title and would like to install it on another PC, first download and install the EA Download manager on the other PC then launch the application and log in with your ea account ..."

I tried to install the download manager (with success) I managed to 'confirm' my product code (again with success as TT appeared in my library) but when I start the game and enter my credentials (with success) it asks the product key which gives the error above.

What can I do ?

W