Pixels in decimal
Establishes the width of the rectangle that Windows 2000 uses to detect double-clicks. If sequential clicks are positioned within the rectangle defined by DoubleClickHeight and DoubleClickWidth, and occur within the time specified by DoubleClickSpeed , they are interpreted as double-clicks. Otherwise, they are interpreted as sequential single clicks.
To view and change the value of this entry, applications should use the SystemParametersInfo API.