Alt+F1

Open the Main Menu at the location of your mouse pointer.

You can customize this keyboard shortcut. 

Alt+F2

Open the Run Program dialog.

You can customize this keyboard shortcut. 

Print Screen

Take a screenshot of the entire screen.  

You can customize this keyboard shortcut. 

Alt+Print Screen

Take a screenshot of the window that currently has focus. 

You can customize this keyboard shortcut. 

F1

If the focused desktop element is an application window or dialog, this keyboard shortcut opens the online help for the application. 

Ctrl+ F1

If the focused desktop element is a panel or application window, this keyboard shortcut switches the display of tooltips for the window or panel objects on and off. 

Shift+ F10

Open a popup menu for the desktop element that has focus, if a popup menu exists.