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: * [http://www.microsoft.com/security/scanner/default.aspx Microsoft Safety Scanner] * [http://www.malwarebytes.org/products/malwarebytes_free/ MalwareBytes' Anti-Malware] * [http://support.kaspersky.com/faq/?qid=208283363 TDSSKiller - AntiRootkit Utility] * [http://www.surfright.nl/en/hitmanpro/ Hitman Pro] * [http://www.eset.com/us/online-scanner/ ESET Online Scanner] [http://windows.microsoft.com/MSE 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!

You can also try [http://www.mcafee.com/de/downloads/free-tools/stinger.aspx McAffe Labs Stinger] which is a one-click solution (no installation, but no permanent security!). It will scan the computer only once.

Run Adwcleaner, Spybot and Spyhunter. You should also go through list of programs installed in last week or so. Typically,[http://www.2-viruses.com/remove-adchoices Adchoice] and similar comes together with some sharewares.

You can remove it manually. http://helpremoveviruses.blogspot.com/2013/12/how-to-remove-adchoices-pop-up-virus.html