How do I get dual monitors to work?

I have an nvidia 8400 GS 512mb video card. My monitor is connected to the video card via DVI, while the projector is connected via VGA. I got them both to work, except that the projector isn't displaying my desktop. The projector is doing this weird thing, where I have to drag something from the monitor to the right, and off the screen. Then it shows up on the projector. I dont want this. I want BOTH, the PJ and the Monitor to be displaying my desktop. Is this possible?