Dell OptiPlex 790 SDT Core i5-2500 3.30GHz 4GB 250GB WINDOWS 7 PRO 64-BIT DVD+/-RW Processor: Intel Core i5-2500 3.30GHz; 4 Cores, 4 Threads; 6MB L3 Shared Cache; Memory: 4GB DDR3 Installed; Hard Drive: 250GB 3.5" SATA Operating System: Windows 7 Professional 64-Bit Installed and Activated; with Recovery Partition and COA (Certificate Of Authenticity); Optical Storage: CD/DVDRW Super Combo Optical Disc Drive; Power Supply: 250 Watt Graphics: Intel HD Audio; Audio: Integrated High Definition Audio Device; Communication: Integrated Intel 82579LM Gigabit Ethernet Controller 10/100/1000 GBE Front I/O Ports: Four USB 2.0 Ports, One Headphone / Output Jack, One Microphone / Input Jack Rear I/O Ports: Six USB 2.0 Ports, One Audio Input Jack, One Audio Output Jack, One RJ-45 Ethernet Port, One VGA Connector, One Display Port, One Serial Port, Two PS/2 Ports (one keyboard, one mouse)