Hello,

First try start Firefox in Safe Mode:

• Start Firefox in Safe Mode

Second, try scan your computer:

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
• TDSSKiller - AntiRootkit Utility
• 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!

Yeah, safe mode does not make it work correctly either - the problem persists

Now you need only check what addon is doing this.

This topic will help you;

• Disable or remove Add-ons

Try disable one addon by one until you find the cause of problem.

You may have something like the classic "Google redirect virus" which is a difficult malware infection to remove because it involves a rootkit that enables it to hide on your system. TDSSKiller (linked above) would be the best place to start if that's what you have.

Also please check your Firefox connection setting here:

orange Firefox button (or Tools menu) > Options > Advanced > Network mini-tab > "Settings" button

The default is "Use system proxy settings" but I suggest trying "No proxy" to see whether that makes any difference.