Intel® C++ Compiler XE 13.1 User and Reference Guides
To add a source file to the hello_world project:
Select the hello_world project in the Project Explorer view.
Select File > New > Source File. The New Source File dialog box opens.
The dialog box automatically populates the source folder for the source file to be created. You can change this by entering a new location or selecting Browse.
Enter hello_world.c in the Source File field.
Click Finish to add the file to the hello_world project.
In the Editor view, add your code for hello_world.c.
When your code is complete, Save your file.