looks to me like you have not set up your search directories and/or linker options in your projects build options properly.
It seems that he doesn't have any project at all.
So...
Menu: File ->New -> Project
Select the one you want. (since you already have source, I think the empty Project could be a good start).
Then
Menu: Project -> Add files... (or recursively)
to add your existing files into the project.
Then
Menu: Project -> Build options...
to set up your configuration like include directories, libraries, ...