Sorry the version is 34.0.5 not 43 that was a typo.

Firefox at Mozilla.org installers only have Firefox. Some places use their own installers to download Firefox, and God knows what.

Download Firefox Full Installer For All languages And Systems {web link}

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 these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP 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!

The Yahoo edition of Firefox is from https://downloads.yahoo.com/firefox/

Firefox from mozilla.org for Windows, Mac OSX and Linux is clean as it does not come with extras including the Vosteran.

Note that as of Firefox 34 the en-US Firefox has the search engine changed to Yahoo as the default and not Google. This is not the same as the Yahoo edition.

Your answers helped, but did not resolve the entire problem.

I do have additional problems that I thought I has asked along with this one.

I've used many of the suggested free downloads. The only program found that would remove the Vosteran virus was Spy Hunter. In fact it was the only one that detected it. Anyway that virus has been removed no thanks to any of the anti malware I have tried before now.

I removed the Firefox for yahoo installation. And replaced it with the Mozilla download Firefox Setup Stub 34.0.5 exe. It seems to be working just fine, other than I still do not have the minus--plus on the drop down menu on this computer. The Screen shot Menu drop down button shows that drop down on this computer at this time.

The menu dropdown 1 shows the drop down button on my other computers giving me the minus--plus feature on the drop down menu. Can you explain why that is. Why I can not use that feature on this computer.

Type about:customizing<enter> in the address bar. In the new window, look for the icon. When you find it, hold down the left button on it, and move it to where you want it to be. You can move any of the icons you want from here, but some icons are locked in place.

Note that you can also right-click an item in the "3-bar" Firefox menu button drop-down list and use "Move to Toolbar" or reverse it with "Move to Menu" by right-clicking an item on a toolbar. "Remove from Toolbar" will move the item to the Customize palette.

Sorry but I do not see the plus or minus in the about:customizing, nor in the drop down window, using the button. If you look at the screen shots I sent, you will see that on this computer and on the Firefox page, their is not second line under the cut copy and paste line. As there is on the other installed Firefox drop down windows under the above mentioned line.

How would you suggest that I put it into that drop down window, when it is not shown on the customizing page either.

In the first screenshot the zoom controls show on the Navigation Toolbar and in the second screenshot in the "3-bar" Firefox menu button drop-down list. You can right-click this item to move it between the Firefox menu button list and the Navigation Toolbar or move the button manually in Customize mode.

I figured it out all by myself. Your answers were worthless, and did not address the problem.

For your information, the fix was so simple that a child could have done it. There is a reset to default on the bottom of the page. I clicked it out of frustration, to see what it did. It restored the minus, plus feature on the drop down menu. Just like my others computers do.

This closed the issue as far as I am concerned. You will hear no more from me.