Let me start by assuming your system is not "infected" by adware/malware... '''''Skype''''' If the screen similar to the attached screenshot? Programs you install on your system can advertise their add-ons to browsers in the Windows registry. Firefox likely has discovered Skype in the Registry -- I believe it is included with Windows 10 now -- and is asking whether you want to activate it. You may be able to disable the add-on from within the Skype software (outside of Firefox), or simply uninstall Skype to get rid of all of its components. Normally, Firefox should not bother you about the same extension at every startup. There may be a problem with your Firefox settings folder causing your decision not to be remembered, or perhaps some "cleaning" software is removing certain files between Firefox sessions, forcing you to keep making the same settings changes over and over. '''''eBay''''' Firefox doesn't come with an eBay button. This likely is created by an add-on. Now I'm beginning to suspect an infection... Here's my suggested procedure for tracking down and cleaning up bad add-ons, hijackers, and other troublemakers. I know it seems long, but it's not that bad. (1) Open 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. (If in doubt, feel free to post a screenshot.) (2) Open Firefox's '''Add-ons page''' using either: * Ctrl+Shift+a * "3-bar" menu button (or Tools menu) > Add-ons * in the Windows "Run" dialog, type or paste <br><code>firefox.exe "about:addons"</code> 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. ''Bear in mind that all extensions are optional.'' 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. Any improvement? (3) You can search for remaining issues with the '''scanning/cleaning tools''' listed in our support article: [[Troubleshoot Firefox issues caused by malware]]. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case.