That's annoying. Some thoughts:

(1) Have those tabs been saved in your home page setting? In that case, they would appear in every new window you launch (Ctrl+n).

Check your home page setting for possible extra vertical bars ("|"). Firefox uses that to specify separate home tabs. This article will get you to that area of the Options page: Startup, home page, tabs, and download settings.

If unwanted pages return after you exit Firefox and start it back up again: Check this article: How to fix preferences that won't save.

(2) Is this part of restoring an earlier session? Two signs of that would be:

(A) Only your active tab loads, the other two load "on demand" when you click them, and (B) The Restore Previous Session command on the History menu is grayed out.

If these are from a previous session, you can hide all previous sessions from Firefox before your next startup. Steps for that later in this post.

(3) Is your desktop shortcut "hacked"?

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?

(4) Do you have a rogue extension?

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
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions. Then cast a critical eye over the list on the right side. Any extensions that Firefox installs on its own are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything suspicious? If in doubt, disable.

Often a link will appear above at least one disabled extension to restart Firefox before the change takes effect. You can complete your work on the tab and click one of the links as the last step.

Any improvement?

If you need to hide old session history files from Firefox:

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows Explorer.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > "power" button
• (menu bar) File > Exit

Pause while Firefox finishes its cleanup, then:

(A) rename sessionstore.js to something like sessionstoreX.js (by default, Windows doesn't show the .js extension, but says the file type is JScript). If you see a file named sessionstore.bak, delete it, that is very obsolete.

(B) rename the sessionstore-backups folder to something like sessionstore-backupsX (just in case you need these files in the future).

When you start Firefox up again, it should just go to your home page.

By the way, if that's more than you want to tackle, you could try Firefox's Refresh feature. It will handle #1 and #4 on that list, but not #2-#3. To learn more about the option, see: Refresh Firefox - reset add-ons and settings.

After struggling with this for some time, the fix was surprisingly simple. With Firefox running: Tools>Options>Home Page>Restore to Default. Restarted Firefox. Unwanted tabs did not reload!! Went back to: Tools>Options>Home Page>Use Bookmark and entered preferred bookmark. All back to normal now. Thanks!

edited per flag - angles changed LTR