There may be some innocent-sounding programs that are maintaining the infection. Also, if you use Advanced SystemCare or other utility/privacy/security software that blocks browser settings changes, those can frustrate your cleanup efforts by rolling you back to older settings. I suggest running through these steps again: (1) Start with the Windows '''Control Panel''', Uninstall a Program. After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Take out as much trash as possible here. (2) Then, in Firefox, open the '''Add-ons page''' using either: * Ctrl+Shift+a * "3-bar" menu button (or Tools menu) > Add-ons In the left column, click Plugins. Set nonessential and unrecognized plugins to "Never Activate". In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions. Often 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. (3) Search for remaining issues with the '''scanning/cleaning tools''' listed in our support article: [[Troubleshoot Firefox issues caused by malware]]. Note that the tools are free and take considerable time to run. If they seem to finish quickly and then ask for payment, you might have a Fake AV infection. Please use the specialized forums listed in the article in that case. Success? Also, if you still have your download history, can you try to track down any suspicious downloads around the time of your last update? There might be a fake update site that needs to be shut down.