Hy Maryann, Are you trying to use the built in update feature? If that isn't working, you could also try going to http://www.mozilla.org/en-US/firefox/new/ # Download the full installer for 8.0.1 to your desktop. # Close Firefox. Be sure that it isn't still running in the background. # Run the installer and re-open Firefox. Hopefully this helps!

'''Do not download and try to install the newest 8.0.x ''' see [http://www.mozilla.org/en-US/firefox/system-requirements.html Firefox 8 System Requirements] Firefox 4 versions and later do not run on a PowerPC Mac(that you have) and require at least OS X 10.5 and an Intel Mac. '''latest supported version for your os is 3.6.24 '''you can download from here: http://www.mozilla.org/en-US/firefox/all-older.html see [http://www.mozilla.org/en-US/firefox/3.6/system-requirements/ Firefox 3.6 System Requirements] For older Macs that aren't supported in Firefox 4+ versions if you like try TenFourFox for PowerPC's running Mac 10.4.11 & 10.5.8 http://www.floodgap.com/software/tenfourfox/ http://tenfourfox.blogspot.com/ https://code.google.com/p/tenfourfox/wiki/PluginsNoLongerSupported see also: [https://support.mozilla.com/en-US/kb/Installing%20Firefox%20on%20Mac Installing Firefox on Mac] thank you Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.