After installation of Service Pack 3 and PC restart , enable the product self-defense back.
If the resolution did not help, contact Kaspersky Lab Technical Support by sending a request via the My Account service.
How to enable/disable self-defense in Kaspersky Anti-Virus 2013
Release of antivirus database updates (required to protect your computer/server/mobile device)
Providing technical support over phone / web
Release of patches for the application (addressing detected bugs)
*Installation under Windows 8.1 is not supported by the current version.
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