This field specifies a path to the executable to be run when the View Module in External Viewer command is invoked. You may use environment variables, like %SystemRoot%, in this path.

This field specifies the command line arguments to be passed to the executable specified in the Command field when the View Module in External Viewer command is invoked. You may use a %1 anywhere in the argument string to represent the full path to the module file. When the external viewer application is launched, all %1 tokens will be replaced with the full path to the module file. You should surround all %1 arguments in quotes so that the external viewer can handle long filenames with spaces. For example, "%1". You may also use environment variables in this field.

This button will display a File Open Dialog, which allows you to browse your system for the executable file to be used as your external viewer. If a file is chosen in this dialog, the Command field will be updated to show the new file.

When you first run Dependency Walker, it defaults to using QUIKVIEW.EXE as your external viewer if you have it on your system. If it is not found, then it defaults to using DEPENDS.EXE as the external viewer, which will just launch another instance of Dependency Walker. Here is an example using DUMPBIN.EXE (part of Visual C++) to get header information about a module: