Note: ''"Safe Mode is a debugging startup mode available in Firefox, Thunderbird, and SeaMonkey 2, where all added extensions are disabled, the default theme is used, and default localstore settings (toolbar settings and controls) are used. Safe Mode also disables hardware acceleration, the Just-in-time (JIT) JavaScript compiler, and any changes made via userContent.css and userChrome.css. Any changes made to preference settings remain in effect in Safe Mode, however, and all available plugins are used."'' (Source: http://kb.mozillazine.org/Safe_Mode ) To start in Safe Mode, hold down the Shift key while clicking the Firefox desktop icon for Firefox. *See --> https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode If Firefox is sluggish when in regular mode but not when in Safe Mode, the cause may be one of your extensions. *[https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems Troubleshooting extensions and themes] *[https://support.mozilla.org/en-US/kb/troubleshoot-issues-with-plugins-fix-problems Troubleshooting plugins] *[https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems Basic Troubleshooting] '''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.org/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.org/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.org/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.org/en-US/kb/Using%20the%20Java%20plugin%20with%20Firefox#w_installing-or-updating-java Installing or Updating Java in Firefox]