Get reliable performance from the Optiplex 990, Intel Core i5-2400 3.1GHz quad-core processor 16GB memory - For multitasking power, supports up to 16GB 2TB SATA hard drive has plenty of space to store your digital albums, music library and rich media files Enhanced viewing with the integrated Intel HD 2000 graphics DVD-ROM drive - watch movies on your computer; read CDs and DVDs in multiple formats The front-panel's USB ports make it easy to transfer photos, music, and other files to and from your digital camera and other peripheral devices Windows 10 Professional was designed for on-the-go working professionals. Connect to networks in three clicks, automatically find preferred network printers, give professional presentations, and use business programs with Windows XP Mode Specifications: Processor: Intel Quad-Core i5-2400 3.1GHz (Turbo up to 3.4GHz) 6MB Cache Memory: 16GB (4 slots, supports up to 16GB) Graphics: Intel HD Graphics 2000 Video Ports: VGA, DisplayPort Hard Drive: 2TB HDD (7200rpm) SATA Card Reader: No Optical Drive: DVD-ROM Sound: Integrated Network: 10/100/1000 Gigabit Ethernet Wireless: USB Wifi Adapter I/O Ports: (1) DisplayPort (1) VGA (10) USB 2.0(1) RJ-45 LAN (2) PS/2 (1) Serial (1) Headphone (1) Microphone (1) Audio: Line-in (1) Audio: Line-out Expansion Slots & Bays: (1) Half-Height PCIe x16 Slot (1) Half-Height PCIe x16 (wired x 4) Slot (1) 5.25\\\" External Drive Bay (1) 3.5\\\" Internal Drive Bay Operating System: Genuine Windows 10 Professional 64-bit