Dell OptiPlex 990 SFF Desktop Intel Quad Core i5-2400 3.10GHz 16GB DDR3 RAM 512GB SSD DVDRW WiFi Bluetooth Windows 7 Professional 64-Bit Microsoft Windows 7 Professional 64-Bit pre-installed w/CoA Intel Core i5-2400 3.10 GHz quad-core CPU Intel Q67 Express chip, Intel HD Graphics 2000 16GB DDR3 SDRAM, 512GB SSD, DVD-RW drive Windows 10 Upgradable