HP p6270z PC, Athlon X4 620 Quad-Core 2.6GHz / 4GB / 500GB / Windows 7 for $409.99 shipped.

1. Click here to start and select Customize & Buy for the Base Configuration
2. Click on Review & Buy to add it to the cart
3. Apply coupon code SVMY478761 to drop the price to $409.99 shipped

Here is a screenshot for your reference.  This system features Athlon X4 620 Quad-Core CPU at 2.6GHz, 4GB DDR3 RAM, 500GB hard drive, dual layer DVD burner, memory card reader, Windows 7 Home Premium 64-bit, and more.  Note that you might want to further customize it to fit your specific needs.