Lenovo Desktop ThinkCentre M90p Core i5 Dual-Core 3.20GHz Bus Speed 2.50GT/s 4 MB Cache RAM 4GB 500GB SATA DVD Multiburner Gigabit Enabled (1.00 Gbps) Local Area Network Capable Microsoft Windows 7 Professional (32-bit) License Only - No OS Installed U.S. English Desktop Ultra Small Form Factor Black with 150W AC Adapter