It should work, but you have an older PCIe 1.0 slot and most 560 cards are at least PCIe 2.0. I have heard of occasional problems with this. It will possibly also run slightly slower due this fact. I would google the cards name and model number along with the phrase "in a PCIe 1.0 slot" and see what you find.
You will also need at least a good quality 450-500 watt power supply to run that card. And by good quality, I mean at least an 80 plus certified .