Lenovo Thinkpad T431s 14-Inch, i5, 4GB, 500GB Notebooks 20AA000BUS Windows 7 Professional 64 preinstalled through downgrade rights in Windows 8 Pro 64-bit Intel Core i5-3337U 1.8GHz Processor with Turbo Boost Technology 2.0 up to 2.7GHz 3MB Smart Cache 500GB SATA Hard Drive + 24GB SSD 4GB PC3-12800 1600MHz DDR3 RAM (12GB max) Manufacturer Warranty: 3 Years