it's ok to keep it in the same folder if you only want to upgrade and not have 2 programs.
the shortcuts in your start menu will still be pointing to the same place, so when you click
firefox, it'll open the new version in that folder. let us know if you need help setting up firefox,
since you're probably worried about everything working in the new version.
Edited by cogs10, 21 June 2011 - 10:43 PM.