Function keys The F1 through F12 keys? "Function keys", F1 through F12 may have a variety of different uses or no use at all. A program is capable of not only using each of the function keys, but also combining the function keys with the ALT or CTRL key, for example, Microsoft Windows users can press ALT + F4 to close the program currently active. S hort-listing of some of the common functions of the functions keys on computer s running Microsoft Windows are given below F1 Almost always used as the help key, almost every program will open the help screen when this key is pressed. Enter CMOS Setup. Windows Key + F1 would open the Microsoft Windows help and support center. Open the Task Pane.