Aspire E5-531P-P3Z4 Touchscreen Notebook. OS: Windows 8.1 (64-bit) Processor: Intel Pentium Processor 3556U (2MB Intel Smart Cache, 1.70GHz) Memory: 4GB (4/0) DDR3L SDRAM Storage: 500GB SATA hard drive, 5400RPM; integrated Super-Multi drive; SD card reader LED TFT LCD: Glossy 15.6" (1366 x 768) 10-point touchscreen Graphics: Integrated Intel HD Graphics (200MHz base frequency, 1.0GHz max dynamic frequency) This new model differs from the E5-531-P4SQ / NX.MLVAA.002 in four ways: Windows 8.1 OS, touchscreen display, black chassis and slight difference in the height and weight..