Get a double molex to single pci connector, you will need two free molex connectors coming from your PSU to do this, but it will give you the connector you need. DON'T BUY A SINGLE MOLEX TO SINGLE PCI CONNECTOR, the wires will actually get hot enough to melt, trust me, I'v tried. Also, your system should have at least a 600 watt PSU, if it doesn't have a 600+ psu, I would recommend you upgrade, or you will burn up components in your system... PSU's can be found for $20-300 new on ebay or $70ish-400 new on newegg.