"C:\Program Files (x86)\Mozilla Firefox\firefox.exe"

First check whether these four tabs are configured as your home pages. One way to do that is launch a new window using Ctrl+n. Another way is to close three of the tabs and then click the Home button. If either of those give you the four tabs again, you need to clean up your home pages setting. More info in this article: [[How to set the home page]]. If your home page setting is good, then here are two other things to investigate: '''''Investigate Your Shortcut''''' The Firefox icon can be set up to launch specific pages at startup (or more specifically, when you use the icon). To check whether that is set: First, open the shortcut as follows: * Desktop shortcut: right-click the icon, choose Properties * Pinned taskbar icon: right-click the icon, right-click Mozilla Firefox, choose Properties Windows normally will select the Shortcut tab. If not, go ahead and click the Shortcut tab. You'll see the Target highlighted. On 64-bit Windows, that usually is no more and no less than the following: "C:\Program Files (x86)\Mozilla Firefox\firefox.exe" If anything follows after that, try clearing it out. After OK'ing the Properties dialog, you can test right away to confirm that Firefox now launches only your home page. Either: * double-click desktop shortcut * right-click pinned taskbar icon, click Mozilla Firefox Success? '''''Investigate Extensions''''' You can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either: * Ctrl+Shift+a (Mac: Command+Shift+a) * "3-bar" menu button (or Tools menu) > Add-ons In the left column, click Extensions. Then cast a critical eye over the list on the right side. All extensions are optional. If in doubt, disable. 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?