ChoosePixelFormat Access violation reading location

I'm trying to create a simple OpenGL context but the program crashes on ChoosePixelFormat with the error "Unhandled exception at 0x779CE0E6 (ntdll.dll) in OpenGL.exe: 0xC0000005: Access violation reading location 0x00000044." This same code used to work a while back but for some reason doesn't work anymore. I tried updating my graphics drivers to no avail. If it matters, I have a 64-bit Windows 7 Home premium, a GeForce 570 and a Intel Core i7-2600 3,40 GHz.

This is the code I use in the order of execution to the point it crashes:

GLEngine gl(WndProc); //WndProc just calls DefWindowProc
- calls ->
GLEngine::GLEngine(WNDPROC wndproc) { //Initialize class

    hRC = NULL;
    hDC = NULL;
    hWnd = NULL;
    fullscreen = false;
    active = false;

    proc = wndproc;
    itemsLength = 0;

    currentActive = this;

    success = true;
}

int APIENTRY _tWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPTSTR    lpCmdLine, _In_ int       nCmdShow) {

    gl.CreateGL2Window("Test", 1300, 900, 8, false, true);

- calls ->

bool GLEngine::CreateGL2Window(char* title, int width, int height, bool internalflag) {

    GLuint pixelFormat;
    WNDCLASSEX wc;

    DWORD dwExStyle;
    DWORD dwStyle;

    RECT windowRect;
    windowRect.left = (long)0;
    windowRect.right = (long)width;
    windowRect.top = (long)0;
    windowRect.bottom = (long)height;

    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance; //hInstance is NULL here, should it be something else?
    wc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = NULL;
    wc.lpszMenuName = NULL;
    wc.lpszClassName = _T("OpenGL");
    wc.hIconSm = NULL;

    if(!RegisterClassEx(&wc)) {

        MessageBox(NULL, _T("Failed To Register The Window Class."), _T("ERROR"), MB_OK | MB_ICONEXCLAMATION);
        return false;
    }
    hInstance = wc.hInstance; //hInstance isn't NULL anymore

    dwExStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;
    dwStyle = WS_OVERLAPPEDWINDOW;

    AdjustWindowRectEx(&windowRect, dwStyle, false, dwExStyle);

    if(!(hWnd = CreateWindowEx(dwExStyle, _T("OpenGL"), 
        (wchar_t*)title, 
        WS_CLIPSIBLINGS | WS_CLIPCHILDREN | dwStyle,
        0, 0,
        windowRect.right - windowRect.left,
        windowRect.bottom - windowRect.top,
        NULL,
        NULL,
        hInstance,
        NULL))) {
            DestroyGLWindow();
            MessageBox(NULL, _T("Window Creation Error."), _T("ERROR"), MB_OK | MB_ICONEXCLAMATION);
            return false;
    }

    if(!(hDC = GetDC(hWnd))) {

        DestroyGLWindow();
        MessageBox(NULL, _T("Can't Create A GL Device Context."), _T("ERROR"), MB_OK | MB_ICONEXCLAMATION);
        return false;
    }

    PIXELFORMATDESCRIPTOR pfd2 = { sizeof(PIXELFORMATDESCRIPTOR),
        1,
        PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
        PFD_TYPE_RGBA,
        32,
        0, 0, 0, 0, 0, 0,
        0,
        0,
        0,
        0, 0, 0, 0,
        32,
        8,
        0,
        PFD_MAIN_PLANE,
        0,
        0, 0, 0
    };
    if(!(pixelFormat = ChoosePixelFormat(hDC, &pfd2)) {

GLEngine is in a dll. It shouldn't matter but the information can't hurt.

Did you get address of function with GetProcAddress? Faulty drivers can cause crash on this too. ChoosePixelFormat may be implemented and exported driver-side, but it might be not exported, then system procedure should be used. exported one may or may not filling descriptor structure, depending on implementation, so you need to call DescribePixelFormat.