Lenovo ThinkCentre S50, 2.8 GHz, Intel® Pentium® 4, 0.5 GB, 40 GB, CD-ROM, Windows XP Professional Lenovo ThinkCentre S50. Processor frequency: 2.8 GHz, Processor family: Intel® Pentium® 4. Internal memory: 0.5 GB, Internal memory type: DDR-SDRAM. Total storage capacity: 40 GB, Optical drive type: CD-ROM. Operating system installed: Windows XP Professional. Chassis type: SFF. Product type: PC. Weight: 18.3 lbs (8.3 kg)