Some "free key" websites require you to complete "offers" or download multiple "free items" before showing a code, which is often a method to generate ad revenue or distribute further malware. Account Theft:

Once you have a legitimate key, activating it is straightforward. Let's use a Steam key as an example:

An activation key (or CD key) is a unique string of letters and numbers (e.g., XXXXX-XXXXX-XXXXX) that proves you own the game. You enter this code into a platform like Steam or Battle.net to download and play Modern Warfare II .