From the Project menu, choose Project Options. Select the `Directories` main tab. Select the `Include Directories` sub-tab. In the bottom single-line text-field, type `../../libs/objLoader` Press `Add` then `OK`. From the Project menu, choose `Add to Project.` In the file dialog, choose ../../libs/objLoader.cpp and press `Open`. objLoader.cpp should show up as part of your Dev-Cpp project. Consider creating the folder structure libs/objLoader/objLoader.cpp as in objLoaderExample.dev