1. Open Kaspersky License Manager (from lower right corner).

2. Click ‘Activate the application with a new license’ button. 
(Delete any trial key first, by clicking the red X next to the key).

3. Disable your internet connection 
(either disable Network adapter from control panel or turn off your modem/router).

4. Select ‘Activate commercial version’ and enter the activation license code as 11111-11111-11111-1111X
or select ‘Activate trial license’.

5. Click Next, an error dialog box will open as shown below:

6. Click Ok and you will now get the option to activate kaspersky using a key file.

7. Browse to the key location and activate kaspersky.