Hi, to recover non-restored windows, check either of these: * "3-bar" menu button > History > Restore Previous Session * (menu bar or Alt+S) History > Restore Previous Session If they are missing or grayed, check either: * "3-bar" menu button > History > Recently Closed Windows * (menu bar or Alt+S) History > Recently Closed Windows * Ctrl+Shift+N (reopens the last closed window) ---- ''But back to a possible cause:'' Sometimes windows go off screen or become non-visible for other reasons. Could you check the Firefox View tab -- either: * click the file drawer icon at the left end of the Tabs bar * type or paste '''about:firefoxview''' in the address bar and press Enter to load it Once Firefox View opens, click Open Tabs in the left column. This should show a box for each open Firefox window. If you have a window there that is not visible on screen somewhere, there's your trouble. You can close its tabs or try to figure out if it's on a different Windows desktop (hold down the Windows key and then tap and release Tab and release the Windows key to move windows between desktops). Finally, as a side note, Firefox doesn't use the Java plugin (JRE) any more, so no need to update Java for Firefox's sake.