Operating System : Windows 10 Home & Pro MAR Chipset : Intel Q170 PCH-H Vpro Processors : Intel Core I3, i5, I7 6th Gen Memory Support : Four (4) DIMM slots , Up to 64 GB DDR4 - 2133 Hard Drive : SSD-PCIe,G2 SSD-PCIe, Sata 7.200rpm or SSD or SSHD Removable Media : HP 9.5mm Slim Desktop DVD-ROM ODD/DVDRW/BDXL Blu-Ray Drive Expansion Bays : External: One (1) 9mm Slim ODD Internal: Two (2) 3.5inch, One (1) 2.5inch Expansion Slots : Two (2) PCIe x1 v3.0, Two (2) PCIe x16 v3.0, Graphics : Intel HD Graphics Audio : HD audio with Realtek ALC221 codec Communications : Intel  I219LM Gigabit Ethernet Port I/O Ports : Front: Two (2) USB 2.0 (one includes fast charging), Two (2) USB 3.0, Audio I/O Rear: Six (6) USB 3.0, VGA, Two (2) DP, RJ-45, PS/2, Serial, Audio I/O Input Devices : Standard Keyboard, Mouse (USB or PS/2) Power : 280 W, up to 92% efficient, active PFC; 400 W, up to 92% efficient, active PFC Dimensions : 100 x 381 x 337 mm Weight : 9.4 KG