For games registered with or purchased from Electronic Arts such as "The Sims 3," serial numbers and activation codes are available through the Origin online system. If the game was a retail purchase and not registered, Electronic Arts live chat game advisors can assist with activation.
Electronic Arts games purchased on Amazon also use the Origin system. "The Sims 3" is available from Steam, too. If purchased there, Steam software allows users to download games again and keep any activation keys in account records.
Used physical game purchases require contacting Electronic Arts support, possibly providing copies of the game manual and additional money for activation. Used game purchases are not guaranteed to work, and Electronic Arts does not support installation if the previous owner still has a copy of the game.