Operating System :Windows 7 Home & Pro. MAR, Windows 10 Home & Pro MAR, Ubuntu Linux, Free DOS Chipset :Intel® PCH C206 Processors :Intel® Xeon? processor E3 family, 2nd gen Intel® Core™ processor family, Dual-Core Intel Pentium processors Memory Support :Four (4) DIMM slots for DDR3 PC3-10600 ECC, 16GB Max Hard Drive :250GB to 2TB SATA 3.0-Gb/s, 160GB to 256GB SSD Drives Removable Media :16X DVD-ROM SATA Drive, 16X DVD+/-RW SuperMulti SATA Drive, Blu-ray Writer Expansion Bays :External: One (1) 5.25-inch, One (1) 3.5-inch, Internal: One (1) 3.5-inch Expansion Slots :1 PCI Express slot x1 (LP), 1 PCI Express slot x16 (LP), 1 PCI Express slot x16 (x4) (LP), 1 PCI slot (LP) Graphics :Integrated Intel HD Graphics Media Accelerator Audio :Integrated Intel/Realtek HD ALC261 Audio Communications :Intel Gigabit CT Desktop NIC I/O Ports :Front: Four (4) USB 2.0, Headphone/Mic, Rear: Six (6) USB 2.0, 2 PS2, Serial, Audio I/O, DVI-I, DP Input Devices :Standard Keyboard (USB or PS/2) Mouse (USB or PS/2) Power :240 watts wide-ranging, active Power Factor Correction, 89% Efficient Dimensions :100mm x 338mm x 381mm (3.95" x13.3" x15.0" in) Weight :7.6 kg (16.72 lbs)