Is Firefox stuck in full screen view? The F11 function key switches between full screen and regular views. The Firefox's window is an irrational size in regular view, it can indicate some corruption in the file which stores window location/dimension information. The usual medicine is to rename that file and let Firefox restart using default dimensions. Here's how: 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? Since this process probably turns off most of the toolbars, you can use one of these methods to show the toolbar list and turn on 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.

Thank you, jscher2000! I must have accidentally hit F11 at some point.