g_hhk = SetWindowsHookEx(WH_KEYBOARD, KeyboardProc, hInstance, NULL);

UnhookWindowsHookEx(g_hhk);

LRESULT CALLBACK KeyboardProc(int code, WPARAM wParam, LPARAM lParam)
{
  if (nCode < 0 &#0124;&#0124; nCode == HC_NOREMOVE)
    return CallNextHookEx(g_hhk, nCode, wParam, lParam);
 
  if (!(lParam & KF_UP))
  {
    // Es wurde eine Taste mit dem virtuellen Key-Code wParam gedrückt. Loggen wo auch immer man will
  }
}

#include "windows.h"
#include "winuser.h"
#include <stdio.h>
#define WIN32_LEAN_AND_MEAN
#define AppName "Main"
 
//CALLBACK Functions
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
LRESULT CALLBACK KeyboardProc(int,WPARAM,LPARAM);
 
//Initialisations
HWND hwnd;
HWND hwnd2;
HWND btnEnd;
HINSTANCE hIn;
 

HDC hdc;
PAINTSTRUCT ps;
 

//WinMain-Fucntion
int WINAPI WinMain(HINSTANCE hInstance,
		   HINSTANCE hPrevInstance, 		   LPSTR lpCmdLine,
	  	   int iCmdShow)
{
	MSG msg;
	WNDCLASS wc;
 
	wc.cbClsExtra = 0;
	wc.cbWndExtra = 0;
	wc.hbrBackground = (HBRUSH) GetStockObject(LTGRAY_BRUSH);
	wc.hCursor = LoadCursor(NULL,IDC_ARROW);
	wc.hIcon = LoadIcon(NULL,IDI_APPLICATION);
	wc.hInstance = hInstance;
	wc.lpfnWndProc = WndProc;
	wc.lpszClassName = AppName;
	wc.lpszMenuName = NULL;
	wc.style = CS_HREDRAW | CS_VREDRAW;
 
	RegisterClass(&wc);
	char WinDir[MAX_PATH];
	char* DllName;
 
	char DllDir[255];
	
	DllName = "\system32\kbdgr.dll";
	
	GetWindowsDirectory(WinDir,MAX_PATH);
 
	_snprintf(DllDir,sizeof(DllDir),"%s%s",WinDir,DllName);
	
 
	hwnd = CreateWindowEx(NULL,
		AppName,
		AppName,
		WS_POPUPWINDOW,
		50,
		50,
		150,
		100,
		NULL,
		NULL,
		hInstance,
		NULL);
 
	ShowWindow(hwnd,iCmdShow);
	UpdateWindow(hwnd);
 

	HANDLE hand  = GetCurrentThread();
	hIn = LoadLibrary(DllDir);
	if ( hIn != NULL )
		SetWindowsHookEx(WH_KEYBOARD,KeyboardProc,hIn,GetCurrentThreadId());
	else
		MessageBox(hwnd,DllDir,"Error",NULL);
 

	while(GetMessage(&msg,NULL,0,0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}
 
	FreeLibrary(hIn);
 
	return msg.wParam;
}
 
LRESULT CALLBACK KeyboardProc(int code,WPARAM wParam,LPARAM lParam)
{
	MessageBox(NULL,"KeyDown",NULL,NULL);
	return 0;
}
 
LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
	LPTSTR Text;
	int MaxChar = 2;
 
	switch(message)
	{
		case WM_DESTROY:
			PostQuitMessage(0);
			return 0;
		case WM_CREATE:                           
      return 0;
		case WM_SIZE:
			break;
		}
 
	return DefWindowProc(hwnd,message,wParam,lParam);
}