Hi Cindy, could you describe the symptoms in a little more detail? Specifically:

• Did the unwanted site take over your entire home page? You can test by launching a new window (Command+N). If so, check the Home page setting: How to set the home page.

• Did the unwanted site take over your entire new tab page? You can test by launching a new tab (Command+T). If so, that usually is due to an add-on.

• Did the unwanted site make itself your default search engine for the address bar? You should be able to switch it on the Settings/Preferences page, but if there is a rogue add-on, that might not be effective. It's worth a try: Change your default search settings in Firefox.

• Any other odd behaviors or symptoms?

If you can't get control of those settings, most likely the problem is one of your add-ons that didn't appear suspicious on the first check. Let's give those a closer look. Here's how:

Open the Add-ons page. Either:

• Command+Shift+a (Windows: Ctrl+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. On the right side, find the "Manage Your Extensions" heading.

If there is at least one extension before the next heading -- "Recommended Extensions" -- please continue:

Then cast a critical eye over the list below that heading. Any extensions Firefox installs for built-in features are hidden from this page, so everything listed here is your choice (and your responsibility) to manage. Anything that mentions search, or privacy, or looks suspicious, or that you just do not remember installing or why? If in doubt, disable (or remove). For your privacy and security, don't let mystery programs linger here.

Any improvement?

If your Add-ons page is blank or is blocked, you can restart Firefox in its Safe Mode to do the above review:

In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to bypass issues that can cause problems with pages.

If Firefox is running:

You can restart Firefox in Safe/Troubleshoot Mode using either:

• "3-bar" menu button > Help > Troubleshoot Mode... (before Fx88: Restart with Add-ons Disabled)
• (menu bar) Help menu > Troubleshoot Mode... (before Fx88: Restart with Add-ons Disabled)

and OK the restart. A small dialog should appear. Click the Open button (before Fx88: "Start in Safe Mode" button).

If Firefox is not running:

Hold down the option/alt key when starting Firefox. (On Windows, hold down the Shift key instead of the option/alt key.) A small dialog should appear. Click the Open button (before Fx88: "Start in Safe Mode" button).

Note: Don't use the Refresh without first reviewing this article to understand what will be deleted: Refresh Firefox - reset add-ons and settings.

Can you regain control of your default search engine/home page/new tab?

The OP has a reply with screenshot in /questions/1383588

Hi Cindy, thank you for the screenshot. What were the steps leading up to that page loading? Was when you first started Firefox, or after you took an action (what action?) in Firefox?

The address of this thread is: https://support.mozilla.org/questions/1383561

Sorry -- to complete the thought:

When you are entering text in the address bar, Firefox will show you what it intends to do if you press Return at that moment (or click the Go button at the right end of the bar). Does that show the unwanted search site there?