To add a file, click Files -> "Add File". The file properties editor dialog will appear.

To mark the file as virtual, select the "Virtual file" checkbox. Virtual file is a file which will be embedded in the resulting exe. The path where the virtual file will be created when the application starts is specified in the virtual path field. It can be (and normally is) a relative path.

For example, an application, when it starts, loads the file 1.txt from the folder with the application itself. You do not want to spread the file around. Thus, you will need to add a virtual file. Select the file with the data that are to be contained in 1.txt and then specify 1.txt for the virtual path.

When the application starts, it will "think" that the file 1.txt is actually stored nearby. In the reality, the file can be missing.

To add the plugin, add it by clicking on the "Choose..." button. Plugins can also be embedded in the exe to be generated or, they can be stored along with it.

Finally, you can specify that the file you have added is an ActiveX / COM library, and it needs to be registered in the virtual registry when the application starts.