Lenovo ThinkPad P50 20EN001EUS 15.6-inch Laptop (2.70 GHz Intel Core i7-6820HQ, 16 GB RAM, 256 GB SSD, NVIDIA Quadro M2000M, Windows 7 Pro) Operating system: win 10 Pro 64-bit / win 7 Pro 64-bit downgrade - pre-installed: win 7 Pro 64-bit Processor: Intel Core i7 (6th Gen) 6820Hq / 2.7 GHz ( 3.6 GHz ) / 8 MB cache Memory: 16 GB DDR4 Maximum Memory Capacity: 64GB