To do the Activation of Security Retail card just follow the website mcafee activate & then it will ask you to enter the 25 characters long McAfee product key. Once you have entered the correct McAfee code & other details correctly on activation screen then you can start the download and installation of your Antivirus Security Online. If you have any issue while doing this please give us a call or simple start the free live help chat with one of our online expert. First you need to make sure that there are no other security program installed in your operating system then you need to activate your registration number on the website mcafee activate. Once you have completed the activation process you can login to your McAfee Account and go to subscription section of your account and then you can see the button there like Add device. Now you can start the download and installation of your McAfee product online.