Dual windowing in MPR view lets you duplicate a group of result images. Dual windowing lets you manipulate the original group and the duplicated group independently with different values, such as zooming, panning, and performing window level changes. Dual windowing options are:
None: The images return to the original result image view.
Horizontal: The original images display horizontally, and the duplicate images appear below.
Vertical: The original images display vertically, and the duplicate images appear on the side.
1. From the PowerViewer toolbar, click Dual Windowing 
.
2. Select an option.
You can set different values for the duplicated images, such as different windowing or zoom values.