Windows 7 Professional Installed by a Microsoft Authorized Refurbisher Dell Optiplex 620 Tower, Fast and Powerful 3.4GHz Pentium D Dual Core Processor, 4GB DDR2 High Performance Memory, Large 500GB SATA Hard Drive, DVDRW/CDRW, Wireless Capable (Adaptor Sold Separately), Ships and Sold by EzbuyCafe