Licenses bought starting mid August 2018
Open the Start Center and click Show details in the lower right corner.
Click the Free Edition (or whatever your current Edition is) text below the logo to open the license overview window.
In the license overview window, open the Your License tab and click the Enter a new License Key button.
If you do not see the Enter a new License Key button, you must download and install the latest Spybot updates.
Enter the license key you received (it can be found either on the Purchase Confirmation page, your Purchase Receipt email, and your invoice PDF) and you’re ready to go.
Licenses bought before August 2018
You will have received a link to your license installer by email. Please download and execute this installer.