Try changing the settings.

Sorry, that's not a built-in feature, most likely it's malware. 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
  firefox.exe "about:addons"

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.

Can you get back to normal?

Also, your plugin list is full of old versions which could provide a vector for infections. When you come up for air:

Flash

These are obsolete now:

• Shockwave Flash 13.0 r0
• Shockwave Flash 21.0 r0

You should use Adobe's uninstaller to clean all Flash off the system, then install the current Flash 22 plugin for Firefox.

• https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html
• https://get.adobe.com/flashplayer/ (make sure to uncheck any unwanted extras)

Adobe Acrobat/Reader

These are obsolete now:

• Adobe PDF Plug-In For Firefox and Netscape 10.1.16
• Adobe PDF Plug-In For Firefox and Netscape "9.5.0"

Windows 10 can run Adobe Reader XI, which is the last version with a normal interface, and is still getting security patches. You can get the download from this page:

https://get.adobe.com/reader/enterprise/

• Select version 11.0.10
• After installing, update with the latest patches using the menus inside Adobe Reader: Help > Check for Updates

That should update Firefox automatically, but if the older versions aren't cleared from your list, I can recommend how to delete them by hand.

This page displays a list of your plugins with version numbers for quick reference or pasting here: https://www.jeffersonscher.com/res/plugins.html