IE8 support is spotty at times, and lower than that I think is just plain not supported. I know that Chrome runs on XP (I don't remember if/when support was dropped) and that Firefox does as well (same words about dropping support) but I am pretty sure that those ancient versions of FF you mentioned are not HTML5 compliant.
I understand your frustration. My wife is a school teacher and is frustrated on a daily basis at the IT crap that she finds. Computers are not like buildings (buy it once and it lasts forever if you take care of it) yet that is the way they are treated.
TLDR: If you can't run an HTML5 compatible browser your life with Angular will be extremely difficult.