In most cases, Perceptive Search will be able to activate (launch) documents properly without user interaction, in some cases they may require to be manually configured.
With a document format selected on the left of the screen, this option tells Perceptive Search to use its own internal settings to activate or print documents in that format. This is the default option.
With a document format selected on the left of the screen, this option tells Perceptive Search to use the associations set up in Windows for that document format. Perceptive Search will activate the document using the same method that would be used if you double-clicked the document in Windows Explorer.
With a document format selected on the left of the screen, this option tells Perceptive Search to use the nominated application with the appropriate DDE codes for activating or printing that document format. In this situation, Perceptive Search is acting in a DDE client role. You will need to refer to your program's technical documentation to ensure the correct syntax and commands for using this section.