Lenovo ThinkCentre M800 10FW0005US Desktop Computer (Intel Core i5-6500 3.2 GHz- 4 GB DDR4 Memory- 500 GB HDD - Intel HD Graphics 530 - Windows 7 Professional 64-Bit ) Processor: Intel Core i5-6500 Processor (6M Cache, 3.2GHz) Operating system: Windows 7 Professional 64 - English (Downgraded from Genuine Windows 10 Professional) Graphics: Intel HD Graphics 530- Memory: 4GB PC4-2133MHz DDR4 UDIMM Memory 500GB, 7200RPM Serial ATA 3.5" Hard Drive - DVD Recordable Serial ATA Lenovo USB Preferred Pro Full Size Keyboard - English and Lenovo Optical Wheel Mouse USB