If you receive an error message, ‘Invalid Key File’, while using Kaspersky Internet Security then you should reinstall your security solution. First, uninstall the security solution by opening ‘Control panel’, choose ‘Programs and Features’. Now select the security solution further click on ‘Uninstall. Now, download the installer for that security solution that you will find on ‘Official Kaspersky Lab Website’. Then, restart your computer and further run the installer by following the installation steps and instructions. At last, use activation key to activate security solution.
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