Hello,

Does the toolbar show up when you launch Firefox in safe mode once?

When you start in Firefox's Safe Mode, all extensions are temporarily disabled, hardware acceleration is turned off and the default theme is used. This will help determine whether one of these is causing your problem.

• At the top of the Firefox window, click the Firefox button, go over to the Help menu and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog.

Note: You can also start Firefox in Safe Mode by holding down the shift key while starting Firefox.

• When the Firefox Safe Mode window appears, press the button Start in Safe Mode.

After Firefox starts in Safe Mode, test for your problem.

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Please reply back to us.

The Yahoo! Toolbar shows in the System Details List as an installed extension.

Yahoo! Toolbar 3.1.0.20130813024103

You can check for problems caused by a corrupted localstore.rdf file.

• http://kb.mozillazine.org/Corrupt_localstore.rdf

It is possible that there is a problem with the file(s) that store the extensions registry.

Delete the extensions.* files (e.g. extensions.sqlite, extensions.ini) and compatibibility.ini in the Firefox profile folder to reset the extensions registry.

• https://support.mozilla.org/kb/Profiles

New files will be created when required.

See "Corrupt extension files":

• http://kb.mozillazine.org/Unable_to_install_themes_or_extensions
• https://support.mozilla.org/kb/Unable+to+install+add-ons

If you see disabled or not compatible extensions in "Firefox/Tools > Add-ons > Extensions" then click the Tools button at the left end of the Search Bar to check if there is a compatibibility update available.

If this hasn't helped then also delete the addons.sqlite file.