If you're having trouble connecting to the Call of Duty: Modern Warfare, you should first check Call of Duty: Modern Warfare Server Status. If the status indicator for your platform is not green or an alert is present, you might encounter connectivity issues until service is restored and fully operational.

Run a security scan to remove any viruses or malware infections. Try creating a new administrator account to resolve permissions issues. Uninstalling and reinstalling the Blizzard App may resolve rare launcher issues.