Registering The Sims Medieval game and to your Origin account via the Sims 3 website:

1. Go to http://www.thesims3.com and make an account if you do not already have one. If you already have an account, skip to step 2. If you already have an Origin account, please use the same email and password to register on http://www.thesims3.com.
2. Once you are a registered member of http://www.thesims3.com, login to your account so that you can then register your game codes.
3. Click on the My Page tab.
4. Then click the My Account tab.
5. Click on Register a Game.
6. Enter the product code for the expansion pack or stuff pack.
7. Click the green Register button.