How to activate Kaspersky license using a key file :
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.
Source - www.viruscut.blogspot.com
