Windows: If you have a window that you want to keep open without risk of accidental closure, NoClose gets the job done. The lightweight application disables the X button in the Windows titlebar for the windows you select. Select the window you want to lock and then hit CTRL+1 to lock and unlock the window. You can also add rules for Windows so that NoClose will remember which windows you want locked. While locking your work station when you're away is the best way to keep things just as you left them, NoClose is a great solution to keep an errant mouse click or moment of thoughtlessness from closing a window or application you need open. NoClose is freeware, Windows only.