Beginning with Firefox version 4, MACs are required to have *Mac OS X 10.5 or higher and *an Intel processor; you have an Intel processor. *System requirements: [https://www.mozilla.org/en-US/firefox/4.0/system-requirements/index.html Firefox 4]   [https://www.mozilla.org/en-US/firefox/5.0/system-requirements/index.html Firefox 5]   [https://www.mozilla.org/en-US/firefox/6.0/system-requirements/index.html Firefox 6]   [https://www.mozilla.org/en-US/firefox/7.0/system-requirements/index.html Firefox 7]   [https://www.mozilla.org/en-US/firefox/8.0/system-requirements/index.html Firefox 8] '''If this reply solves your problem, please click "Solved It" next to this reply when <u>signed-in</u> to the forum.''' ------------------------- Not related to your question, but... You may need to update some plug-ins. Check your plug-ins and update as necessary: *Plug-in check --> http://www.mozilla.org/en-US/plugincheck/ *Adobe Shockwave for Director Netscape plug-in: [https://support.mozilla.com/en-US/kb/Using%20the%20Shockwave%20plugin%20with%20Firefox#w_installing-shockwave Installing ('''''or Updating''''') the Shockwave plugin with Firefox] *Adobe PDF Plug-In For Firefox and Netscape: [https://support.mozilla.com/en-US/kb/Using%20the%20Adobe%20Reader%20plugin%20with%20Firefox#w_installing-and-updating-adobe-reader Installing/Updating Adobe Reader in Firefox] *Shockwave Flash (Adobe Flash or Flash): [https://support.mozilla.com/en-US/kb/Managing%20the%20Flash%20plugin#w_updating-flash Updating Flash in Firefox] *Next Generation Java Plug-in for Mozilla browsers: [https://support.mozilla.com/en-US/kb/Using%20the%20Java%20plugin%20with%20Firefox#w_installing-or-updating-java Installing or Updating Java in Firefox]