Try http://www.mozilla.org/en-US/firefox/all-older.html

how do you get back to older firefox softwear

You should find your language and operating system from that list.

For example, if you are on a mac, and you speak english, you would scroll down to the english row, and select the Mac OS X column, then it would direct you to http://download.mozilla.org/?product=firefox-3.6.23&os=osx&lang=en-US

For an unofficial Firefox 7 compatible version (TenFourFox) that runs on PowerPC Macs with OS X 10.4.11 or OS X 10.5.8 you can look at:

• http://www.floodgap.com/software/tenfourfox/
• http://www.macupdate.com/app/mac/37761/tenfourfox