On my Logitech G510s the Start (Windows) key wouldn’t work and when I pressed the Windows / Start key nothing happened…
The keyboard actually wasn’t broken, the Logictech G510s is designed to do this when it’s in “Game playing mode”. This is to prevent you from accidentally pressing the Windows / Start key when playing a game. Also it allows you to reprogram the Windows / Start key so it can be used in games.
To make the Windows / Start key work on the Logitech G510s, slide the toggle (slider switch) above the F1 key to the left. The Windows / Start key should now work on the Logitech G510s.