If you have received a retail card after purchasing your subscription, then you may need to activate your subscription using the retail card. However, those who make online purchase of McAfee, need to undergo a little different procedure of McAfee activate. For the retail card activation, you need to use the code provided in the retail card. On the other hand, you need to copy the activation code from the welcome/confirmation mail from McAfee and enter it when asked at the mcafee.com/activate portal. For this, navigate to the web address mentioned on the retail card and enter the 25 digit McAfee activation key. Further, enter the required details correctly on the activation screen. Once you have entered the details, you are all set to download and activate your product.