The latest version of Kaspersky Antivirus and Internet Security (2010) does not allow to activate your Kaspersky product using a license key file i.e. without an activation code.
The 2010 Kaspersky Lab products can be activated only by an activation code via theInternet. This becomes quite difficult if you have a valid license key file or want toActivate Kaspersky Products Offline.
Though, 2010 build don’t have the option to activate using the key file but there is a trick to do it 
Activation Kaspersky 2010 license using key file:
1. Open your Kaspersky 2010 License Manager.
2. Click Activate New License.
3. Select Activate commercial license and enter the activation license code as T1JVS-NNMBD-K1QTN-SUBP8 (beta code).
4. Click Next. Now you’ll get a dialog box as shown below, click Ok on it.
5. That’s it. Now you will see the option of a key file to activate your KAV/KIS 2010product.
Browse to the key location on your PC and activate your product easily.
UPDATE – Activating Kaspersky 2010 (ver 9.0.0.736) using key file.
As pointed out by some readers, the above trick does not work when activating KAV/KIS (v 9.0.0.736) with a key file. Here is a working way which lets you do this task. Follow the steps below carefully –
1. Open Kaspersky License Manager.
2. Click Activate New License (Delete any trial key first, by clicking the red X next to it).
3. Disable your internet connection (either disable Network adapter from control panel or turn off your modem/router).
4. Select Activate commercial license 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. Browse to the key location and activate kaspersky.
Haxmania's World 