|ENVI User's Guide: Display Management|
To start a new, independent Image window, select Window Start New Display Window from the Image window menu bar or from the ENVI main menu bar.
Each window started is numbered sequentially starting with Display #1. You can also open a new Image window using the New Display option in the Available Bands List (see Selecting the Active Display).
ENVI Online Help (August 12, 2005)