I would guess that the 2 pin connector is just for a fan if there is one on the graphics card. It shouldn't need to be connected. The 200W should be fine as that card doesn't draw much power.
However that is not your problem. It appears that you bought a PCI express card and your system has an AGP graphics port. The two are not compatible. You will need to purchase an AGP graphics card for it to work. You listed it as PCI but I was unable to find a PCI HD3450. Also PCI is different than PCIe.
Try this HD 3450http://www.newegg.com/Product/Product.aspx?Item=N82E16814139053
I was able to find a PCI 3450 graphics card after some additional searching but 99.9% were PCIe. Please confirm that yours is PCI, not PCI express (PCIe). Also please confirm you inserted it in the correct slot. PCI slots will be white and closer to the bottom of the Motherboard while AGP ports are usually brown and closer to the Processor.