Dell OptiPlex 3020 Intel Quad Core i5-4590T 2.0GHz 4GB 500GB Windows 8.1 Pro Micro Desktop (Certified Refurbished) This Certified Refurbished product is tested & certified by Dell to look and work like-new. The product includes all original accessories, and is backed by a 1 Year warranty Microsoft Windows 8.1 Pro 64-bit pre-installed 4th Gen Intel Core i5-4590T Quad-Core 2.0GHz CPU 3GHz Max Turbo Frequency, 6MB Intel Smart Cache, 5GT/s DMI2 4GB DDR3 SODIMM (supports up to 16GB) with 500GB hard drive Integrated Realtek RTL8151GD 10/100/1000 Gigabit Ethernet