I want to learn GLFW for making GUI app, so I installed it and placed it in the include folder of gcc (mingw32). I wrote that code :

#include <GL/gl.h>
#include <GLFW/glfw3.h>

int main(int argc, char* argv[]) {
    glfwInit();

    GLFWwindow* window = glfwCreateWindow(720, 480, "Test", NULL, NULL);

    while (!glfwWindowShouldClose(window)) {
        glClear(GL_COLOR_BUFFER_BIT);
        glClearColor(0.1f, 0.1f, 0.1f, 1.0f);

        glfwPollEvents();
        glfwSwapBuffers(window);
    }

    glfwDestroyWindow(window);
    glfwTerminate();
    return 0;
}

And I entered this command:
gcc main.c -o main.exe -lglfw -lgl

Note : I use Windows 10

I tried to install gcc again but it doesn’t work.