You can only relocate a corner window into another qualified L-shaped wall joint. Right-click the location grip and press Ctrl to cycle through the following options: 
-  Specify Wall Corner. Drag the location grip to another qualified wall corner. 
 
-  Move Within. Move within the wall by specifying an offset distance. The same offset value is applied to both the window panes of the corner window. 
 
-  Move Vertically. Move the corner window vertically along the wall height.