The JAWS screen reader default is in the Virtual PC Cursor mode.
On a user interface where you press Enter to activate the default action after pressing Enter to make a selection, JAWS causes the second Enter to be ignored. To activate the default action, you must tab to the button corresponding to the default action and then press Enter. For example, when you add a document, you have the option to select a document class. After you tab to the class you want, press Enter to select the class. When not using JAWS, you can press Enter again to activate the OK button and accept your selection. When using JAWS, you must first tab to the OK button before pressing Enter again.
You can also press the spacebar to activate actions.
On a user interface that includes a combination box, where the capabilities of an entry field and a list box are used for providing a set of options. The JAWS reader recites the numerical position of the currently selected item and the total number of items that are displayed in a list.
Tab to focus the combination box. Press Alt+Down arrow to view the items in the list. Press Insert+Up arrow or Insert+Down arrow and have JAWS read the numerical position of the current selected item and total number items in the list.