Grab screen is used to select a portion of the screen for capture to a new window. To use Grab Screen, select it from Edit/Grab screen or use Ctrl-G from the keyboard. You will then see the cursor change to crosshairs. Go to one corner of the screen image you want to select and click with the left mouse button. Move to the opposite corner and click again. The area you set with the two corners will appear in a new window.