Restart your computer to resolve problems caused by programs and services running in the background. Update your drivers and operating system to resolve any compatibility issues. Configure your security software's exception list to allow Blizzard applications to run.

Disable conflicting software programs: If conflicting software programs are running in the background, Call of Duty: Modern Warfare 3 will not start Update drivers for Razer Synapse and graphics card: Make sure your graphics card and Razer Synapse drivers are up to date Run Steam or Battle as administrator: Make ...