Disable the default browser agent
Supported on: Firefox 75 or later, Firefox 68.7 ESR or later
Registry
HKLM
Software\Policies\Mozilla\Firefox HKCU
Software\Policies\Mozilla\Firefox Value name: DisableDefaultBrowserAgent
Enabled: DisableDefaultBrowserAgent = 1
Disabled: DisableDefaultBrowserAgent = 0
Description
If this policy is enabled, the default browser agent is disabled. If this policy is disabled or not configured, the default browser agent is enabled. For more information about the default browser agent, see https://firefox-source-docs.mozilla.org/toolkit/mozapps/defaultagent/default-browser-agent/index.html