Windows 7 Professional Installed by a Microsoft Authorized Refurbisher HP DC7700 Tower Computer, Featuring Intel's Powerful & Efficient 3.0ghz E8400 Core 2 DUO Processor, Amazing 800mhz Bus Speed & 4MB Cache, 750GB Ultra Fast 7200 RPM Sata Hard Drive, CDRW/DVDRW Sata Ultra Speed Drive, 4GB DDR2 Dual Interlaced High Performance Memory, Wireless Capable;