Could you explain this in a little more detail:

(1) The current version of Firefox is 41.0.2, but your post indicates Firefox 40.0. What version has the problem? You can view your version on the support information page, 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

(2) When you say "closing the tab to adjust computer volume is annoying" do you mean there is no volume control in the tab, or that Firefox is completely blocking access to the Windows taskbar?

If access to the Taskbar is blocked, the first thing to check is that Firefox is not in its Full Screen view. The F11 key switches between full screen and regular views, so I would try that first.

You also could try sliding the mouse pointer to the very top of the screen to pop down the toolbar area and use the "3-bar" menu button to access the Full Screen item on the menu. Sometimes I have to move the mouse up twice or try to the right of my first attempt.

Is that the problem? If not, could you explain in more detail the connection between closing the tab and the computer volume? Thanks.

it is operating in full screen. I can turn it off but it goes back to full screen if I close and reopen the browser, if I open a new tab or close a tab. if I hit the back button or If I try to print by hitting ctrl P. everything makes it go full screen

Hmm, that's odd. I think you may need to remove a possibly corrupted settings file as follows:

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 "Show 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 rename xulstore.json to something like xulstore.old. If you see a file named localstore.rdf, rename that one to localstore.old.

Start Firefox back up again. Do windows display normally again?

To turn missing toolbars back on, you can use one of these methods to show the toolbar list and select the desired bars there:

• right-click a blank spot on the tab bar (or the "+" button)
• tap the Alt key to activate the classic menu bar > View > Toolbars
• in Customize mode > Show/Hide Toolbars (see: Customize Firefox controls, buttons and toolbars)

To turn on the Menu Bar, Bookmarks Toolbar, or other bars, click it on the list.