There is no equivalent in Firefox. You can use the [https://addons.mozilla.org/en-US/firefox/addon/3145/ BlockSite] extension to add a similar feature. If the junk sites are coming up whilst you are browsing, this may be caused by malware. You should consider scanning your computer with some malware programs. It is best to run several as each will pick up things that the others miss. Some scanners you can try are: * [http://www.malwarebytes.org/mbam.php Malwarebytes] * [http://www.superantispyware.com/ SUPERAntiSpyware] * [http://www.lavasoft.com/products/ad_aware_free.php Ad-Aware] * [http://www.microsoft.com/windows/products/winfamily/defender/default.mspx Windows Defender] * [http://www.safer-networking.org/en/home/index.html Spybot S&D]

Other things that need attention:<br> Your above posted system details show outdated plugin(s) with known security and stability risks that you should update. # Shockwave Flash 10.0 r45 # Next Generation Java Plug-in 1.6.0_17 for Mozilla browsers Update the [[Managing the Flash plugin|Flash]] plugin to the latest version. *http://www.adobe.com/software/flash/about/ Update the [[Java]] plugin to the latest version. *http://java.sun.com/javase/downloads/index.jsp (Java Platform: Download JRE)