Dell OptiPlex 755 Mini- Tower, Intel Core 2 Duo 3.33ghz CPU 6M Cache, 4GB DDR2 Memory, *New* 500GB Hard Drive, WiFi, DVD/CD-RW Optical Drive, Microsoft Windows 7 Professional (64-bit) Operating System. Featuring an iCompNY USB Keyboard and Mouse) Dell Optiplex 755 desktop 500GB Hard Drive, WiFi, DVD/CD-RW Optical Drive, Microsoft Windows 7 Professional (64-bit) Operating System