Is it possible to install two versions of firefox (from before and after quantum) while keep all of the add-ons on the same machine? And if yes then how? For almost a year mow I'm sticking to none quantum ver of FF thx to the fact it doesn't work with the addons I want and because nobody updated them, FF also removed them from the addon page so now I must hold to them as if it's my life, they were literally the only reason I moved to FF more than half decade ago from browsers such as IE (And also since I hate Chrome), sure FF is a great browser and my main one as for today but these add-ons save me so much of a work that they are just not wroth to give up on (too bad their creators had abandoned them and that no one made something identical..) So out of depression I want to have two FF versions without losing all of the addons I have on the old one, my question is how I do it and where are all of my settings and addons are so I can backup them in case I'll need to format (I already backup all of the Mozilla and FF folders that are in appdata and C drive so I assume that's was all...), I also want to know if both FF will overwrite each other and if it's possible to stop them? Thx (Also if there's a place where I request from the community to make a addon for FF or teach me how so I can make similar one to the addons I use, please tell me where)