We upgraded Firefox to 5 and are now told that our Advast (antivirus) program will not work with the upgrade. They checked for upgrades to Advast and found none. We do not want to be without Advast. How can we go back to our prior version of Firefox? We tried your auto "help" and didn't get any further than your saying "click on the Firefox button". We can't find the Firefox button. Our computer knowledge is minimal. Please give us detailed help!!