To Activate the Product please check the below source or follow the below procedure:


[KB2792] Activate ESET home and small office products for Windows using the Activation key 



Solution

 Android users |  macOS users

Activate using the activation key

  1. Open the main program window of your ESET Windows product.

  2. When the product activation screen appears, click Use a purchased activation key.

    Figure 1-1

  3. Type or copy/paste your ESET-issued activation key into the Activation key field and click Continue. Ensure you type the activation key exactly as it is, including the hyphens. If you copy/paste the activation key, ensure you do not select additional space around the text. If you do not have your activation key, recover your subscription information. 

    Figure 1-2

  4. Click Activate.

    Figure 1-3

  5. Click Done.

    Figure 1-4