PCI Express? Card won't fit

[Post-Oak]

Looks like I blew it. Obviously I am not the best with computer hardware, so any help is appreciated.

I bought a new video card (the nVidia G-Force 6600) and the damn card won't fit into my computer. I tried putting it into the AGP and the PCI slot.

Now it seems like the reason might be because this card is made for a "PCI Express" slot, and won't fit into a normal PCI slot. Is this correct???