HD is a standard for TVs, not monitors. HD is either 720 or 1080 which indicates the pixel height. 720 being 1280x720 and 1080 being 1920x1080. Monitors have their own resolution, sometimes it is higher, sometimes lower but there is no TV standard. The only standard with monitors is that we traditionally have a 4:3 aspect ratio for square monitors and 16:10 aspect ratio for widescreen. A few have 5:4 like yours (1280x1024 = 5:4)