You will have to be more specific. Have you already updated the CD Key yourself into Origin at any point? It will not accept multiple registrations of that key. If you cancelled the install after registration, your disk software STILL want to register, and Origin won't accept that. You can pause the install, not cancel it, just stop, and when you continue on, you should find it not asking for the unnecessary CD Key (this pause-stop, restart routine is apparently unreliable, however).
If pausing instead of entering the CD Key doesn't work as it should, you can get a free digital copy to download and install that, which may be the easiest fix for you.
Just look up the game in the Origin Client program (game library), and one of your options will be the download.