Activating a Norton key is really easy, simply follow these short steps:

1. Download and Install the latest Norton Security Client through the Norton official link.
2. Install the Norton Security Client on your computer.
3. After installation, please sign into your Norton account or create a new Norton account and sign in the newly created Norton account.
4. In the main window of the installed Norton Security Client, click 'Activate Now'.
5. Enter the purchased 25 bit activation key, then enjoy the full protection of Norton Security Client.

Alternatively, if this method doesn't work for you, then please proceed with those steps:

1. Download the software from this link.
2. Open My Norton.
3. Click on "Open" near to Device Security.
4. Click on "Help" near Settings.
5. Click on "Enter Product Key" under the ACCOUNT INFORMATION list.
6. Enter the product Key in the new window.

Please remember that this product cannot be used to extend your current subscription. The key only activates a new subscription (on a new account or after your current subscription expires).