Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of. You can try some of the following programs to scan for malware: * [http://www.malwarebytes.org/mbam.php MalwareBytes' Anti-Malware] * [http://support.kaspersky.com/faq/?qid=208283363 TDSSKiller - AntiRootkit Utility] * [http://windows.microsoft.com/MSE Microsoft Security Essentials] (A good permanent anti-virus if you don't already have one) Further information can be found in the [[Troubleshoot Firefox issues caused by malware]] article. Did this fix your problems? Please report back to us! _________________________________________________________________________________ In order to uninstall a possibly unwanted extension, please do the following: #From the Firefox window click the Firefox button at the top left and select ''Add-ons'', or, if the Firefox button is not shown, click the ''Tools'' menu and click ''Add-ons''. #Once the Add-on Manager has opened in a new tab, click the ''Extensions'' button on the left side of the window. #You should now see a list of your installed extensions on the right side together with buttons on the right side of each extension. #To remove an extension from Firefox, simply click the ''Remove'' button. You should see a message that informs you about the successful removal of the add-on. #Note that some add-ons require a Firefox restart to be removed completely. To perform a Firefox restart after the add-on removal, click the ''Restart now'' link in the message. You can find further information about uninstalling extensions in the following articles: [[Disable or remove Add-ons]] [[Remove a toolbar that has taken over your Firefox search or home page]]

Firefox 17.0 and above requires Mac 10.6 or higher. The last version made for Mac 10.5.8 is Firefox 16.0.1.

See also: *https://support.mozilla.org/kb/firefox-no-longer-works-mac-os-x-10-5 Latest Firefox for Mac OS X 10.5: *http://ftp.mozilla.org/pub/mozilla.org/firefox/releases/16.0.2/mac/