I have my default browser set to Firefox and have .htm and .html specifically associated with Firefox. But most of my programs that open a browser window open with I.E. instead of my default browser, Firefox. This causes extra wait time for me while I.E. loads and also uses up memory unnecessarily, since I already have a browser open which could have been used.

Does anyone know how to stop that rogue action? It really is frustrating.

   I can think of two reasons why IE is opened instead of Firefox.
   One is that you have missed some associations in the registry.  This you can correct if you figure out what the associations are that you missed and change them.
   The other reason could be that the programs specifically calls for IE to be opened knowing that it is installed on all Windows computers.  If this is the case, there is nothing that you can do.  Windows requires that IE be in the place that it is supposed to be, there is nothing that you can do about that.