Business users: How do I receive a License Key for my ESET business product?

• Obtain your Activation Key. If you do not know your subscription key, request to have your Activation Key emailed to you. Request to have your Activation Key emailed to you.

• Use the Activation Key that was generated for you and sent to the email address you provided while registering/purchasing a subscription.

  • Activation Key example: XXXX-XXXX-XXXX-XXXX-XXXX
  • Copy/paste your Activation Key into the activation screen. Do not copy any extra blank spaces
    
    

• If you cannot copy/paste, type your Activation Key exactly how it is written:

  • The hyphens in the Activation Key are necessary
  • The Activation Key is twenty characters long
  • A big '0' is the number zero (0), and a little 'o' is the lowercase letter o
    
    

• If your Activation Key still does not work:

  • My Activation Key is not working
  • I changed my email address
  • Your subscription might have expired, renew your subscription
  • If you do not know the expiration date of your subscription, visit the Lost subscription page to have this information emailed to you
  • You never received an email from ESET containing your Activation Key
  • If you recently renewed your subscription, wait 24 hours before downloading new ESET product versions or upgrading
  • I changed my email address
  • Ensure you downloaded the correct product for your subscription (check your receipt or subscription email from ESET)
  • Ensure you are downloading the right ESET product build for your computer
  • Clear the update cache in your ESET Windows home product.

Source : [KB2388] My Activation Key is not working