How to change or update a Battle.net account email address.
How to attach an Authenticator to your Battle.net account
Your account is unable to log into Blizzard services.
How to install Call of Duty: Vanguard and troubleshooting steps for technical issues
Troubleshooting for issues loading the BattleTag or Real ID friend list
Possible causes for hearing odd sounds, voices, and effects while playing
Failed to launch Agent or AgentSwitcher. Please close all other applications, temporarily deactivate your anti-virus software, and try again. Alternatively, log in as an administrator and try again.