Lenovo ThinkPad R51, 1.6 GHz, 38.1 cm (15"), 1024 x 768 pixels, 0.5 GB, 30 GB, Windows XP Professional Lenovo ThinkPad R51. Processor frequency: 1.6 GHz. Display diagonal: 38.1 cm (15"), Display resolution: 1024 x 768 pixels. Internal memory: 0.5 GB, Internal memory type: DDR-SDRAM. Total storage capacity: 30 GB. Operating system installed: Windows XP Professional. Weight: 2.6 kg