Ok! Have moved from Windows 7 to Windows 10 and am now on Thunderbird Version 52 (i have tried later versions, and the problem is still there). it appears that you can no longer in full screen mode click in the to-left corner to get the Windows control menu that lets you Restore/Minimise/Close the Thunderbird window. The menu CAN be got by pressing ALT-Spacebar but i want to be able to do it with my mouse .. as i have always done .. for the last ten years. You should also be able to get this menu by right-clicking anywhere along the title bar, but when you do this, you now get the menu that says "Menu Bar... Mail Toolbar... Folder Pane.. Customize". When what i want and expect to see is the standard Windows menu. This is driving me mad, and will have to stop using Thunderbird if if can't do this, and find a mail client that can...! Anyone? Help! thanks, Geoff.