Car Cuts Off And Engine Light Is On

Could This Be A Battery Or Alternator, The Car Cuts Off, Then Coast, I Put It In Park It Cranks, Engine Light Remains On. Then Sometimes I Need A Boost, Sometimes The Windows Wont Work And Then Suddenly All It Back To Normal

It Could Be Both really cuz with what you said about the windows seems like there is a not enough power from the battery but the alternator give power to the battery . So Try changing the battery maybe your gonna be lucky and its just gonna cost you a battery or a new alternator..