DisableWinKey is a quick and dirty tool for Windows that was designed to prevent the Windows key from launching the Start Menu and stealing focus from your application. Particularly useful if you are prone to hit the Windows key instead of the Ctrl or Alt keys in full screen games.

DisableWinKey doesn't actually disable the Windows key, like its name implies. It just prevents the Start Menu from stealing focus when you press it. It also prevents Ctrl+Esc from working, incidentally.