Help > Internet Connectivity (Mathematica Menu Item)

Internet Connectivity opens the Internet Connectivity tab in the Preferences dialog.

Window > Messages (Mathematica Menu Item)

Messages displays the Messages notebook.

File > New > Notebook (Mathematica Menu Item)

Notebook creates a new notebook.

Cell > Grouping > Open All Subgroups (Mathematica Menu Item)

Open All Subgroups opens all groups in a selection.

Help > Register this Mathematica... (Mathematica Menu Item)

Online Registration opens the Mathematica registration website.

Edit > Select All (Mathematica Menu Item)

Select All selects all cells in the current notebook.

Show Breakpoints Window toggles the Breakpoints window on or off.

Cell > Cell Tags > Show Cell Tags (Mathematica Menu Item)

Show Cell Tags toggles the display of cell tags in a notebook.

Show Debugger Tools Window toggles the display of the Debugger Tools window on or off.

Show Stack Window toggles the display of the evaluation stack window on or off.