Mozilla has now included Firefox Hello as system add-on in Firefox 45, you can only notice or discover this when you visit about:support or troubleshooting information page in the browser. Firefox doesn’t show it in add-ons manager to disable or uninstall it, but you can still remove Firefox Hello System add-on, here is how.
Removing Firefox Hello system add-on
Soon Pocket will also be turned into a system-add-on (work is in progress), at present, you can’t deactivate or remove Hello add-on through (by using) Firefox browser. However, we’ve found a way to do that
1.Ensure Firefox is not open, navigate to C:\Program Files\Nightly\browser\features and delete email@example.com xpi file.
Note: when Firefox is on the release channel, then in the above step you should need to visit C:\Program Files\Firefox\browser\features
2. This deletes Firefox Hello add-on and the feature from browser completely, open the browser and check for presence of Hello icon on the navigation bar or in the customize area to confirm.
Note: When you upgrade to a new version, Hello might get re-added to the browser again (we’re not sure about this), you can’t prevent this from happening, then you’ve to follow.above steps to get rid of the add-on again.
But the good news is Refreshing Firefox doesn’t re-add deleted Hello add-on to the browser again.