DPI scale and screen resolution

sys.HDPUScale,,u2	DPI scale & screen resolution
sys.VDPUScale,,u2
sys.HResolution,,u2
sys.VResolution,,u2

These read-only variables contain:

sys.HDPUScale	The horizontal DPI scale.
sys.VDPUScale	The vertical DPI scale.
sys.HResolution	The horizontal resolution of the main display.
sys.VResolution	The verical resolution of the main display.

The DPI scale value is 96 when the user selected scale is 100%. A higher value indicates that the user selected scale is > 100%. See Microsoft documentation for full details as new values are added from time to time to suit new, higher resolution displays.