Operating System : Windows 10 Home & Pro MAR, Ubuntu Linux, Free DOS Chipset : Intel Q75 Express Processors : Intel Core i5 3rd Gen Memory Support : Four (4) DIMM slots , Up to 32 GB UDIMM, PC3-12800 1600MHz DDR3 Hard Drive : 500GB, 1TB (7,200 rpm) or 128GB SSD Removable Media : DVD-ROM/DVD Recordable/Slim DVD-ROM/Slim DVD Recordable Expansion Bays : External: Two (2) 5.25-inch, One (1) 3.5-inch, Internal: Two (2) 3.5-inch Expansion Slots : One (1) PCI Express x16, One (1) PCI Express x1, Two (2) 32-bit PCI 2.3 Graphics : Intel HD Graphics Audio : Realtek ALC662 codec Communications : One gigabit ethernet port, Intel 82579 I/O Ports : Front: Two (2) USB 2.0, Audio I/O  Rear: Four (4) USB 3.0, Two (2) USB 2.0, Audio I/O VGA, DP Input Devices : Pro USB Keyboard (USB connector), 104-key, black, Lenovo logo, Optical Wheel Mouse (USB connector), 400 dpi, black, Lenovo logo Power : 280 watts with variable speed fan, manual switch Dimensions : 175 x 442 x 414 mm Weight : 11.0 kg