Dell OptiPlex 390 SDT Core i3-2120 3.30GHz 4GB 250GB DVD+/-RW WINDOWS 7 PRO 64-Bit Processor: Intel Core i3-2120 3.30GHz; 2 Cores, 4 Threads; 3MB L3 Cache;Memory: 4GB DDR3 Installed; Hard Drive: 250GB 3.5" SATA Operating System: Genuine Dell Windows 7 Professional 64-Bit Installed with Recovery / Reinstallation Partition and Certificate Of Authenticity; Optical Storage: CD/DVD+/-RW DL Super Combo; Power Supply: 250 Watt Graphics: Integrated High Definition Video Controller; Audio: Integrated HD Audio Controller; Communication: Integrated Gigabit Ethernet Controller 10/100/1000 Front I/O Ports: 2 USB 2.0, 1 Headphone / Audio Out, 1 Microphone / Audio In Rear I/O Ports: 6 USB 2.0, 1 HDMI, 1 VGA, 2 Audio In, 1 Audio Out, 1 Ethernet (RJ-45)