If you've ruled out internal settings and extensions, it could be that your Firefox program shortcut was hacked.

Not sure exactly how you do this on Windows 8, but on earlier versions:

right-click the shortcut you use to start Firefox > Properties > Shortcut tab

Check the "Target" line and make sure there is no URL at the end. By default, the target ends with

firefox.exe"

with no URL after it.

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:

PLEASE SCAN WITH ALL PROGRAMS

• 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!

See also:

• https://support.mozilla.org/kb/remove-toolbar-has-taken-over-your-firefox-search-

If this is the startup page then also check the target line in the Firefox desktop shortcut and remove any trailing data after the path to the Firefox program.

Thanks! That solved the issue

I just wanted to add that the DoSearches browser hijacker does add its own URL to the end of the Target field of your Firefox shortcuts. Ref:

• http://malwaretips.com/blogs/dosearches-com-virus/#shortcuts

You should also scan for malware as suggested earlier - see Troubleshoot Firefox issues caused by malware