Does Internet Security Services work with 3rd party anti-virus or firewall software?
No. You must remove any other anti-virus or firewall software before installing Internet Security Services. There is no real benefit to running another anti-virus software, since Internet Security Services includes multiple scanning engines, which work in unison to provide you with the latest active heuristic scanning and disinfection engine. If you are already using an older version of Internet Security Services, the installer will automatically remove it before installing the latest version.