d3d11 not working right

#include <windows.h>
#include <stdio.h>
#include <assert.h>
#include <D3D11.h>


#define D3DCALL( obj, m ) obj->lpVtbl->m( obj )
#define D3DCALL_( obj, m, args... ) obj->lpVtbl->m( obj, args )
#define SAFE_RELEASE( obj ) if( obj ){ D3DCALL( obj, Release ); obj = NULL; }


#define MY_WINDOW_CLASS "myWindowClass"

// Step 4: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {
    case WM_CLOSE:
        DestroyWindow(hwnd);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    WNDCLASSEX wc;
    HWND hwnd;
    MSG Msg;
    HRESULT hr;

    DXGI_SWAP_CHAIN_DESC swapChainDesc;
    ID3D11Device* device = NULL;
    ID3D11DeviceContext* context = NULL;
    IDXGISwapChain* swapChain = NULL;
    ID3D11Texture2D* backBuffer;
    ID3D11RenderTargetView* rtView;

    wc.cbSize        = sizeof(WNDCLASSEX);
    wc.style         = 0;
    wc.lpfnWndProc   = WndProc;
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance     = hInstance;
    wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
    wc.lpszMenuName  = NULL;
    wc.lpszClassName = MY_WINDOW_CLASS;
    wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION);

    if(!RegisterClassEx(&wc))
    {
        MessageBox(NULL, "Window Registration Failed!", "Error!",
            MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    hwnd = CreateWindowEx(
        WS_EX_CLIENTEDGE,
        MY_WINDOW_CLASS,
        "The title of my window",
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, 1000, 800,
        NULL, NULL, hInstance, NULL);

    if(hwnd == NULL)
    {
        MessageBox(NULL, "Window Creation Failed!", "Error!",
            MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

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

    swapChainDesc.BufferDesc.Width = 800;
    swapChainDesc.BufferDesc.Height = 600;
    // - default refresh rate
    swapChainDesc.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
//  swapChainDesc.BufferDesc.ScanlineOrdering = DXGI_MODE_SCANLINE_ORDER_PROGRESSIVE;
//  swapChainDesc.BufferDesc.Scaling = DXGI_MODE_SCALING_STRETCHED;
    swapChainDesc.SampleDesc.Count = 1;
    swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    swapChainDesc.BufferCount = 1;
    swapChainDesc.OutputWindow = hwnd;
    swapChainDesc.Windowed = TRUE;
//  swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
//  swapChainDesc.Flags = DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH;

    hr = D3D11CreateDeviceAndSwapChain(
        NULL, // adapter
        D3D_DRIVER_TYPE_HARDWARE,
        NULL, // software rasterizer (unused)
        0, // flags
        NULL, // feature levels
        0, // ^^
        D3D11_SDK_VERSION,
        &swapChainDesc,
        &swapChain,
        &device,
        NULL,
        &context
    );
    assert( SUCCEEDED( hr ) );

    const GUID myguid_ID3D11Texture2D = {0x6f15aaf2, 0xd208, 0x4e89, {0x9a,0xb4, 0x48,0x95,0x35,0xd3,0x4f,0x9c}};
    hr = D3DCALL_( swapChain, GetBuffer, 0, &myguid_ID3D11Texture2D, (void**) &backBuffer );
    assert( SUCCEEDED( hr ) );
    assert( backBuffer );
    D3DCALL_( device, CreateRenderTargetView, (ID3D11Resource*) backBuffer, NULL, &rtView );
    assert( rtView );
    D3DCALL_( context, OMSetRenderTargets, 1, &rtView, NULL );

    D3D11_VIEWPORT vp;
    vp.Width = 800;
    vp.Height = 600;
    vp.MinDepth = -1.0f;
    vp.MaxDepth = 1.0f;
    vp.TopLeftX = 0;
    vp.TopLeftY = 0;
    D3DCALL_( context, RSSetViewports, 1, &vp );

    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);

    while(GetMessage(&Msg, NULL, 0, 0) > 0)
    {
        // Uncomment this line to create problems for WM_KEY* events to translate messages
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);

        float ClearColor[4] = { 0.2f, 0.225f, 0.3f, 0.3f };
        // here be dragons... or something
        // only the blue color is written, others are set to 0
        // if I pass a valid pFeatureLevel pointer to D3D11CreateDeviceAndSwapChain, no colors are written
        D3DCALL_( context, ClearRenderTargetView, rtView, ClearColor );

        D3DCALL_( swapChain, Present, 0, 0 );
    }

    SAFE_RELEASE( rtView );
    SAFE_RELEASE( backBuffer );
    SAFE_RELEASE( swapChain );
    SAFE_RELEASE( context );
    SAFE_RELEASE( device );

    return Msg.wParam;
}