When you download firefox, it will install a new browser for you. Your internet explorer will stay unaffected. In fact, you will be able to use both at once if you wish.
I'm not sur what the SBCYahoo homepage is, but firefox will not affect anything other than just itself. You may also remove it, and bring your computer back to the state it was before installation.
Upon first run of firefox, it will inquire you upon whether you want it to be your "default" browser. If this is true, then accept. If you wish to keep internet explorer, or whatever the yahoo thing is, then just deny, and you will simply have to open firefox yourself when you wish to use it.
Hey..I am a computer newbie. I am interested in downloading the Firefox 1.0 browser. My basic concern is if I can do this safely without negatively affecting my already existing SBCYahoo DSL connection. Suggestions? What happens when I download it? Does it simply replace my default internet Explorer browser without affecting my already existing SBCYahoo homepage? Thanks for any helpful info. PS I am running on a Windows XP platform.