How to Install Webroot on New Computer If you recently got your new PC/MAC. then you got webroot internet security plus key code. To download follow steps below and Activate your license key. Open the browser (Chrome, Microsoft Edge, safari ) Enter the link www.webroot.com/safe on to the address bar. It will redirect to the webroot installation page, enter the product key. The key code is 20 digit alpha-numeric & it can be found by scratching the card on email if you have purchased online. Click on submit after putting the key. The setup file will automatically download on your system.