Ok,, found the proper way to remove (not disable as you want it removed, not disabled) INBOXACE from both Firefox and IE.
It will take a few moments and I will add all instructions to THIS post. That said, I will post this and add to it as I go...
Bear with me for a few minutes....
How to remove extensions and themes
At the top of the Firefox window, click on the Firefox button (top left), and then click Add-ons. The Add-ons Manager tab will open.
In the Add-ons Manager tab, select the Extensions or Appearance panel.
Select the add-on you wish to remove.
Click the Remove button.
Click Restart now if it pops up. Your tabs will be saved and restored after the restart.
You will see the INBOXACE add on right on top. Far right side click REMOVE.
For Internet Explorer
Open the desktop, and then tap or click the Internet Explorer icon on the taskbar.
Tap or click the Tools button Tools button, and then tap or click Manage add-ons.
Under Show, tap or click All add-ons, and then select the add-on you want to delete.
If the add-on can be deleted, you'll see the Remove option. Tap or click Remove and then tap or click Close.