Stores the default right edge position of the Preview Window dialog box when it was last used. This value will change if the dialog box is resized or moved and will be recalled when the dialog box is subsequently opened. The specified number provides the location of the right edge of the window from the left edge of the screen.
To help you visualize this, the image below has two rectangles, an orange rectangle that represents your screen dimensions, and a green rectangle that represents the position of the Preview Window dialog box.
This setting controls the distance between the left edge of the screen (A) and the right side of the window (D).
Entry Name: PreviewWindowPositionRight
Entry Type: Whole number that specifies the pixels from left edge of screen. The default value is 0.