Here’s a step by step process for activating kaspersky 2011 version. Please follow those instructions and you will able to activate Kaspersky 2011 with just a keyfile
To Activate Kaspersky 2011 license using key file:
1. Open Kaspersky 2011 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 T1JVS-NNMBD-K1QTN-SUBP8 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.
