what language you like

Firefox 4 versions and later do not run on a PowerPC Mac. Firefox 4 and later require at least OS X 10.5 and an Intel Mac. http://www.mozilla.org/en-US/firefox/8.0/system-requirements/ Firefox 3.6.24 (Mac OS X 10.4 and later) can be found here: http://www.mozilla.com/en-US/firefox/all-older.html (this is for you) read the-edmeister reply here too: https://support.mozilla.com/en-US/questions/896057 (A group of Mac users have created their own Community Build from the "Firefox 4+" versions. TenFourFox for PowerPC's running Mac 10.4.11 & 10.5.8 . http://www.floodgap.com/software/tenfourfox/ http://tenfourfox.blogspot.com/ ) Downgrading 1. Visit http://www.mozilla.com/en-US/firefox/all-older.html in your browser. 2. Click Firefox 3.6.24 folder >Mac OS X folder > English (British) language or what language you like 3. Download and install Firefox setup 3.6.24.dmg file You’ll be automatically downgraded to Firefox 3.6.24 and your add-ons, bookmarks and settings will remain. install firefox on mac: https://support.mozilla.com/en-US/kb/Installing%20Firefox%20on%20Mac thank you Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.