Need some help with this capturing keys

Hello,

I found this little code which basicly writes any keystroke to the app
window, however, it only works for the app window. I wanted to modify
it to work when any window is focused, just like key logger.
I'm too new to C++ to figure out this by myself.
Any help would be much appreciated.

Thanks

--- CODE ---
// These make the EXE small (Note: May only work in MSVC).... check out
the exe in the zip
// Start Optimization
#pragma comment(linker, "/MERGE:.rdata=.data")
#pragma comment(linker, "/MERGE:.reloc=.data")
#pragma comment(linker, "/MERGE:.text=.data")
#pragma comment(linker, "/IGNORE:4078")
#pragma comment(linker, "/FILEALIGN:16")
#pragma comment(linker, "/ALIGN:16")
#pragma optimize("gsy", on)
// End Optimization

#include <windows.h>

HINSTANCE hInst;
HHOOK hHook = NULL;
HWND hWndMain = NULL;
HWND hWndEdit = NULL;
char szKey[32];

LRESULT CALLBACK KeyboardProc(int Code, WPARAM wParam, LPARAM lParam)
{
    if(lParam & 0x40000000)
    {
        GetKeyNameText(lParam, szKey, 32);
        SendMessage(hWndMain, WM_USER, 0, 0);
    }
    return CallNextHookEx(hHook, Code, wParam, lParam);
}

BOOL CALLBACK DlgProc(HWND hWnd, UINT uMessage, WPARAM wParam, LPARAM
lParam)
{
    switch(uMessage)
    {
        case WM_CREATE:
            {
                memset(szKey, 0, 32);
                hHook = SetWindowsHookEx(WH_KEYBOARD, KeyboardProc, hInst,
GetCurrentThreadId());
                if(hHook == NULL){
                    MessageBox(hWnd, "Cannot load keyboard hook", "Error", MB_OK |
MB_ICONERROR);
                    return FALSE;
                }
                RECT rcWindow; GetClientRect(hWndMain, &rcWindow);
                hWndEdit = CreateWindow("Edit", "", WS_CHILD | WS_VISIBLE |
ES_MULTILINE | WS_VSCROLL | ES_READONLY,
                    0, 0, rcWindow.right, rcWindow.bottom, hWndMain, (HMENU)1000,
hInst, 0);
            }
            return TRUE;

        case WM_USER:
            SendMessage(hWndEdit, EM_REPLACESEL, FALSE, (LPARAM)"{");
            SendMessage(hWndEdit, EM_REPLACESEL, FALSE, (LPARAM)szKey);
            SendMessage(hWndEdit, EM_REPLACESEL, FALSE, (LPARAM)"}");
            return TRUE;

        case WM_CLOSE:
            EndDialog(hWnd, 0);
            PostQuitMessage(0);
            break;

        case WM_DESTROY:
            UnhookWindowsHookEx(hHook);
            break;
    }
    return DefDlgProc(hWnd, uMessage, wParam, lParam);
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPTSTR lpstrCmdLine,
int nCmdShow)
{
    MSG Msg;
    hInst = hInstance;
    hWndMain = CreateWindowEx(WS_EX_APPWINDOW, "#32770", "Press Any Key",
WS_POPUPWINDOW | WS_CAPTION | WS_VISIBLE,
        ((GetSystemMetrics(SM_CXSCREEN)-400)/2),
((GetSystemMetrics(SM_CYSCREEN)-300)/2), 400, 300, NULL, NULL, hInst,
0);
    if(hWndMain == NULL) return FALSE;

    SetWindowLong(hWndMain, GWL_WNDPROC, (LONG)DlgProc);
    SendMessage(hWndMain, WM_CREATE, 0, 0);
    while(GetMessage(&Msg, NULL, 0, 0)) DispatchMessage(&Msg);

    return 0;
}

--- END CODE ---