Linguagem C - mkdir

#if defined(UNICODE) && !defined(_UNICODE)
    #define _UNICODE
#elif defined(_UNICODE) && !defined(UNICODE)
    #define UNICODE
#endif

#include <windows.h>
#include <math.h>
#include <stdio.h>
#include <tchar.h>
#include <stdlib.h>
#include "Frase.h"

#define BTN1 1
#define BTN2 2
#define BTN3 3

static HWND nome, nome2, num1, num2, num3, num4, resultado;

LRESULT CALLBACK WindowProcedure(HWND, unsigned int, WPARAM, LPARAM);

void addMenus(HWND);

HMENU hMenu;

TCHAR szClassName[ ] = _T("UINT");

int WINAPI WinMain(HINSTANCE hI,HINSTANCE hPI, LPSTR lpszArg, int nCS) {
    HWND       hwnd;
    MSG        messages;
    WNDCLASSEX wincl;

    HBITMAP    imagem;
    HBRUSH     hBrush;

    imagem  = LoadBitmap(hI, IMG);
    hBrush  = CreatePatternBrush(imagem);
    DeleteObject(imagem);

    memset(&wincl, 0, sizeof(wincl));

    wincl.hInstance     = hI;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc   = WindowProcedure;
    wincl.style         = CS_DBLCLKS;
    wincl.cbSize        = sizeof (WNDCLASSEX);
    wincl.hIcon         = LoadIcon(NULL, IDI_QUESTION);
    wincl.hIconSm       = LoadIcon(NULL, IDI_QUESTION);
    wincl.hCursor       = LoadCursor(NULL, IDC_ARROW);
    wincl.lpszMenuName  = NULL;
    wincl.cbClsExtra    = 0;
    wincl.cbWndExtra    = 0;
    wincl.hbrBackground = hBrush;

    if(!RegisterClassEx (&wincl)) {
        return 0;
    }

    hwnd = CreateWindowEx (
        0, szClassName, _T("Evento"), WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, 1036, 375,
        HWND_DESKTOP, NULL, hI, NULL
    );

    ShowWindow(hwnd, nCS);

    while (GetMessage (&messages, NULL, 0, 0)) {
        TranslateMessage(&messages);
        DispatchMessage(&messages);
        FreeConsole();
    }

    return messages.wParam;
}

LRESULT CALLBACK WindowProcedure(HWND hwnd, UINT msg, WPARAM wP, LPARAM lP) {
    switch(msg) {
        case WM_CREATE:
            addMenus(hwnd);

            nome = CreateWindowW(
                L"static", L"Calcular a Media de 4 Notas", WS_VISIBLE | WS_CHILD,
                10, 20, 260, 20,
                hwnd, NULL, NULL, NULL
            );

            CreateWindow(
                TEXT("button"), TEXT(" -> "), WS_VISIBLE | WS_CHILD,
                10, 90, 80, 40,
                hwnd, (HMENU) BTN1, NULL, NULL
            );

            CreateWindow(
                TEXT("button"), TEXT("Nova Pasta no Desktop"), WS_VISIBLE | WS_CHILD,
                110, 90, 180, 40,
                hwnd, (HMENU) BTN2, NULL, NULL
            );

            nome2 = CreateWindow(
                TEXT("static"), DANIEL, WS_VISIBLE | WS_CHILD,
                10, 180, 1000, 20,
                hwnd, NULL, NULL, NULL
            );

            CreateWindow(
                TEXT("static"),"\n\nDaniel 12",WS_VISIBLE|WS_CHILD|DT_CENTER,
                850, 20, 160, 80,
                hwnd, NULL, NULL, NULL
            );

            CreateWindowW(
                L"static", L"1 Nota: ", WS_VISIBLE | WS_CHILD,
                10, 260, 60, 20,
                hwnd, NULL, NULL, NULL
            );

            num1 = CreateWindow(
                TEXT("edit"), TEXT(""), WS_VISIBLE | WS_CHILD | WS_BORDER,
                74, 260, 50, 20,
                hwnd, NULL, NULL, NULL
            );

            CreateWindowW(
                L"static", L"2 Nota: ", WS_VISIBLE | WS_CHILD,
                130, 260, 60, 20,
                hwnd, NULL, NULL, NULL
            );

            num2 = CreateWindow(
                TEXT("edit"), TEXT(""), WS_VISIBLE | WS_CHILD | WS_BORDER,
                196, 260, 50, 20,
                hwnd, NULL, NULL, NULL
            );

            CreateWindowW(
                L"static", L"3 Nota: ", WS_VISIBLE | WS_CHILD,
                256, 260, 60, 20,
                hwnd, NULL, NULL, NULL
            );

            num3 = CreateWindow(
                TEXT("edit"), TEXT(""), WS_VISIBLE | WS_CHILD | WS_BORDER,
                322, 260, 50, 20,
                hwnd, NULL, NULL, NULL
            );

            CreateWindowW(
                L"static", L"4 Nota: ", WS_VISIBLE | WS_CHILD,
                386, 260, 60, 20,
                hwnd, NULL, NULL, NULL
            );

            num4 = CreateWindow(
                TEXT("edit"), TEXT(""), WS_VISIBLE | WS_CHILD | WS_BORDER,
                452, 260, 50, 20,
                hwnd, NULL, NULL, NULL
            );

            CreateWindow(
                TEXT("button"), TEXT("Calcular"), WS_VISIBLE | WS_CHILD | WS_BORDER,
                620, 260, 100, 20,
                hwnd, (HMENU) BTN3, NULL, NULL
            );

            CreateWindow(
                TEXT("static"), TEXT("Resultado:"), WS_VISIBLE | WS_CHILD,
                800, 260, 100, 20,
                hwnd, NULL, NULL, NULL
            );

            resultado = CreateWindow(
                TEXT("edit"), TEXT(""), WS_VISIBLE | WS_CHILD | WS_BORDER,
                910, 260, 100, 20,
                hwnd, NULL, NULL, NULL
            );
            break;
        case WM_COMMAND:
            if(LOWORD(wP)==BTN1) {
                int len = GetWindowTextLength(nome)+1;
                static char title[500];
                GetWindowText(nome, title, len);
                MessageBox(NULL, title, "", MB_OK);
                return 0;
            }
            if(LOWORD(wP)==BTN2) {
                mkdir("C:\\Users\\Student13\\Desktop\\Nova Pasta");

                return 0;
            }
            if(LOWORD(wP)==BTN3) {
                int n1 = GetWindowTextLength(num1)+1;
                int n2 = GetWindowTextLength(num2)+1;
                int n3 = GetWindowTextLength(num3)+1;
                int n4 = GetWindowTextLength(num4)+1;

                static char t1[50], t2[50], t3[50], t4[50];

                GetWindowText(num1, t1, n1);
                GetWindowText(num2, t2, n2);
                GetWindowText(num3, t3, n3);
                GetWindowText(num4, t4, n4);

                if(atoi(t1)==NULL) {
                    MessageBox(NULL, "Campo 1, vazio!", "Alerta", MB_OK);
                    exit(0);
                }
                if(atoi(t2)==NULL) {
                    MessageBox(NULL, "Campo 2, vazio!", "Alerta", MB_OK);
                    exit(0);
                }
                if(atoi(t3)==NULL) {
                    MessageBox(NULL, "Campo 3, vazio!", "Alerta", MB_OK);
                    exit(0);
                }
                if(atoi(t4)==NULL) {
                    MessageBox(NULL, "Campo 4, vazio!", "Alerta", MB_OK);
                    exit(0);
                }

                float res = (atof(t1)+atof(t2)+atof(t3)+atof(t4))/4;

                char tam[30];

                sprintf(tam, "%.2f", res);

                SetWindowText(resultado, tam);

                if(atoi(tam) >= 6) {
                    MessageBox(
                        NULL,
                        "Aluno Aprovado",
                        "Resultado Final",
                        MB_OK
                    );
                }
            }
            break;
        case WM_DESTROY:
            PostQuitMessage (0);
            break;
        default:
            return DefWindowProc(hwnd, msg, wP, lP);
    }

    return 0;
}

void addMenus(HWND hwnd) {

    hMenu = CreateMenu();

    HMENU hFileMenu = CreateMenu();

    AppendMenu(hMenu, MF_STRING, NULL, "Arquivo");
    AppendMenu(hMenu, MF_STRING, NULL, "Editar");
    AppendMenu(hMenu, MF_STRING, NULL, "Propriedade");
    AppendMenu(hMenu, MF_STRING, NULL, "Fonte");
    AppendMenu(hMenu, MF_STRING, NULL, "Keyboard");

    SetMenu(hwnd, hMenu);
}

/******************** Arquivo (.h) ********************/

#define IMG      2
#define DANIEL "E tu, Daniel, fecha estas palavras e sela \
este livro, até ao fim do tempo; muitos correrão de uma parte \
para outra, e a ciência se multiplicará. Daniel 12:4"

/******************** Arquivo (.rc) ********************/

#include "Frase.h"

IMG BITMAP DISCARDABLE "img7.bmp"