Operating System : POSReady 2009, POSReady 7, Microsoft Windows 7 Professional, IBM 4690 OS V6.3 Enhanced, or higher, SUSE Linux 11 (SP2) Processors : Intel Celeron T3100 Memory Support : 665 MHz DDR3 UDIMM 2GB standard 8 GB maximum 2 slots Hard Drive : 500 GB HDD/64 GB SSD option Removable Storage : DVD burner Internal Option (standard on C85) Expansion Slots : 1 PCI, 1 PCI Express standard I/O Ports : Front; One 12 V USB, one headphone, Back; 2 PC USB, 4 RS-232, 1 PS/2 keyboard, 1 PS/2 mouse, Audio mic-in, Audio line out, headphone, 1 RJ45 Ethernet 10/100/1000, 2 VGA Communications : 10/100/1000 Mbps Dimensions : Low profile Distributed 312 mm Χ 451 mm 112 mm, Traditional Narrow: 320 Χ 475 Χ 117.3 mm Weight : Low profile Distributed 10.2 kg, Traditional Narrow: 11.4 kg