Activating a Kaspersky key is really simple, just follow these steps:
Download the software HERE (scroll down the page and download the trial version of the software),
Install the Kaspersky software,
Launch Kaspersky,
Click on the "Enter Activation Code" in the right-bottom corner,
Choose "Activate application" option,
Enter the code and save with "Activate".
Note that the software may require from you to create or login with Kaspersky account