C / C++ / MFC

HANDLE hFile;
DWORD dwFileSize,  dwBytesRead;
LPBYTE lpBuffer;
HANDLE hResource;
	
HRSRC hRes;         // handle/ptr. to res. info. in hExe 
HANDLE hUpdateRes;  // update resource handle 
char *lpResLock;    // pointer to resource data 
HRSRC hResLoad;     // handle to loaded resource 
BOOL result; 
HMODULE hSrcExe,hDestExe;
int iLoop;

hFile = CreateFile("E:\\icon.ico", 
		GENERIC_READ,
		FILE_SHARE_READ,
		NULL,
		OPEN_EXISTING,
		FILE_ATTRIBUTE_NORMAL,
		NULL);

if (INVALID_HANDLE_VALUE != hFile)
{
	dwFileSize = GetFileSize(hFile, NULL);
	lpBuffer = new BYTE[dwFileSize];
	int aa = ReadFile(hFile, lpBuffer, dwFileSize, &dwBytesRead, NULL);
	hResource = BeginUpdateResource("E:\\xyz.exe", FALSE);

	if (NULL != hResource)
	{
		if (UpdateResource(hResource,
				RT_ICON,
				MAKEINTRESOURCE(1),
				MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
				(LPVOID) lpBuffer,
				dwFileSize) != FALSE)
			{        
				EndUpdateResource(hResource, FALSE);
			}
	}
}