How to activate already installed Bitdefender? If you already installed bitdefender latest version, you need not to install / uninstall anything. Just follow below instructions to get it activated. 1. Turn on your pc and open Bitdefender interface by double clicking the bitdefender icon located in your task bar. 2. Click on the “Account Info” tab, which is located on the left sidebar of the Bitdefender interface. The icon will look like a human. 3. Click the “SWITCH ACCOUNT” button to change the account linked to the computer. 4. Type the e-mail address and the password of your account in the corresponding fields, and then click “SIGN IN”. NOTE: The Bitdefender product installed in your device automatically changes according to the subscription associated to the new Bitdefender account. How to install Bitdefender latest version? You can install all Bitdefender 2019 products by following below instructions. Once the installation process is complete, your product will be