The paid versions of Kaspersky's Anti-Virus, Internet Security and Total Security applications require to enter kaspersky activation code a 20-digit license key for activation. Depending on the number of license slots that you purchased, you can use the same license key to activate Kaspersky applications on different computers. If you have lost your Kaspersky license key, you can find it by visiting either the Licensing or the Support pages on your Kaspersky installation.