Alter system volume by program

Alter system volume by program

void SetVolume(DWORD dwVolume)
{

 HKEY    hkResult = NULL;
 DWORD dwSize=0;
 DWORD   dwDisposition;
 int     iResult=1;
 
 if ((iResult=RegCreateKeyEx(HKEY_CURRENT_USER, _T("ControlPanel\\Volume"), (DWORD) 0, TEXT(""),
  REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, (LPSECURITY_ATTRIBUTES) NULL,
  &hkResult, &dwDisposition)) == ERROR_SUCCESS)
 {
  dwSize = sizeof(DWORD);
  RegSetValueEx(hkResult, _T("Volume"), 0, REG_DWORD, (LPBYTE)&dwVolume, sizeof(DWORD));
  
  waveOutSetVolume(0, dwVolume);

  UpdateVolumeFromRegistry();
  
  RegCloseKey(hkResult);
 }

void UpdateVolumeFromRegistry()
{
 HINSTANCE hLibrary = ::LoadLibrary(_T("coredll.dll"));
 
 if (NULL == hLibrary)
  return; 
 FARPROC pProc = ::GetProcAddress(hLibrary, _T("AudioUpdateFromRegistry"));
 
 if (NULL == pProc)
 {
  ::FreeLibrary(hLibrary);
  return;
 }
 
 Proc_AudioUpdateFromRegistry *pProcAudioUpdateFromRegistry = (Proc_AudioUpdateFromRegistry*)pProc;
 
 pProcAudioUpdateFromRegistry();

 ::FreeLibrary(hLibrary);
}

AudioUpdateFromRegistry function is in Coredll.dll implicitly.