Lenovo Windows 8 Operating System and Applications and Drivers Recovery Disc Sets for ThinkCentre M73 Type 10B4,10AX, 10B1 For Thinkcentre M73 Type 10B4, 10AX, 10B1 64-bit software only Operating System Recovery Disc Set of 2 - Windows 8 Pro (OEM Activation 3.0 Required) Applications and Drivers Recovery Disc Set of 2