this is the keyfinder l used to find my windows xp code, it should work however l can prolly find a more updated one if needed.
http://hotfile.com/dl/120349711/0fad...2.0.6.rar.html
as for the upgrade, l have heard of some issues with the latest Firefox but they are mainly down to the fact that some users dont have that great a spec on their systems.. the new firefox uses hardware acceleration, in simpler terms it uses the excess processing power of the graphics cards to bring pages etc to you faster, with regards to proxy settings l dont think they would be an issue unless you specifically edited them before for some reason or another, but by the sounds of it you may not have.