Getting error while deploying WebDynpro Application.

Hi, There

After creating an application for a WebDynpro project, when I execute the project (Deploy New Archive and Run) the application I am receiving then following error message.

"This file does not have a program associated with it for performing this action. Create an association in folder options in control panel."

This message is reflacted for the following file.

"http://......../localhost/prjHello/AppHello?SAPtestId=5"

I am not getting what is the file type of AppHello.xxx file and which file type I have to associate with which program in control panel.

Please give me some idea on which file type I have to associate with which program?