I am upgrading my Windows 7 PC with a new graphics card (PCIExpress). It requires minimum 300W power supply, I only have 200W now. I need to know if an Enermax Tomahawk ETK500AWT 500W ATX12V V2.2 power supply will be compatible. My current power supply is a Dell that came with the original Dimension 2350 PC that I installed the ASRock motherboard in. What replacement power supplies are compatible with my board?

Regards,
pwddad