Can you check your download history to see whether you got an unofficial installer bundle with some unwanted extras from a strange site? To tame the ads, try this: Disable ALL nonessential or unrecognized extensions on the Add-ons page. Either: * Ctrl+Shift+a * orange Firefox button (or Tools menu) > Add-ons In the left column, click Extensions. Then, if in doubt, disable. Usually a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step. Does that flush the extra tabs? If unwanted extensions lack a Remove button, this usually indicates it was installed by other software on your computer. Time to visit the Windows Control Panel, Uninstall a Program, and click "Installed on" to group by date and reveal secret bundled items you may have accepted. Probably best to remove everything recently added that you do not actually know to be useful. Finally, you may want to run some extra scans to mop up any lurking crap. This article lists tools other Firefox users have found helpful: [[Troubleshoot Firefox issues caused by malware]]. Any luck?