win32

#include <tchar.h>
#include <windows.h>
#include <mmsystem.h> // for MCI functions

// Link to winmm.lib (usually included in project settings)
#pragma comment(lib, "winmm")

void ControlCdTray(TCHAR drive, DWORD command)
{
    // Not used here, only for debug
    MCIERROR mciError = 0;

    // Flags for MCI command
    DWORD mciFlags = MCI_WAIT | MCI_OPEN_SHAREABLE | 
        MCI_OPEN_TYPE | MCI_OPEN_TYPE_ID | MCI_OPEN_ELEMENT;

    // Open drive device and get device ID
    TCHAR elementName[] = { drive };
    MCI_OPEN_PARMS mciOpenParms = { 0 };
    mciOpenParms.lpstrDeviceType = (LPCTSTR)MCI_DEVTYPE_CD_AUDIO;
    mciOpenParms.lpstrElementName = elementName;    
    mciError = mciSendCommand(0, 
        MCI_OPEN, mciFlags, (DWORD_PTR)&mciOpenParms);

    // Eject or close tray using device ID
    MCI_SET_PARMS mciSetParms = { 0 };
    mciFlags = MCI_WAIT | command; // command is sent by caller
    mciError = mciSendCommand(mciOpenParms.wDeviceID, 
        MCI_SET, mciFlags, (DWORD_PTR)&mciSetParms);
    
    // Close device ID
    mciFlags = MCI_WAIT;
    MCI_GENERIC_PARMS mciGenericParms = { 0 };
    mciError = mciSendCommand(mciOpenParms.wDeviceID, 
        MCI_CLOSE, mciFlags, (DWORD_PTR)&mciGenericParms);
}

// Eject drive tray
void EjectCdTray(TCHAR drive)
{
    ControlCdTray(drive, MCI_SET_DOOR_OPEN);
}

// Retract drive tray
void CloseCdTray(TCHAR drive)
{
    ControlCdTray(drive, MCI_SET_DOOR_CLOSED);
}

int _tmain(int argc, _TCHAR* argv[])
{
    EjectCdTray(TEXT('E')); // drive letter hardcoded
    CloseCdTray(TEXT('E'));

    return 0;
}

#include <windows.h>  
#include <tchar.h>  
#include <stdio.h>  

int _tmain() 
{ 
   DWORD dwBytes; 
   HANDLE hCdRom = CreateFile(_T("\\.\M:"), GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL); 
   if (hCdRom == INVALID_HANDLE_VALUE) 
   { 
     _tprintf(_T("Error: %x"), GetLastError()); 
     return 1; 
   } 

   // Open the door:  
   DeviceIoControl(hCdRom, IOCTL_STORAGE_EJECT_MEDIA, NULL, 0, NULL, 0, &dwBytes, NULL); 

   Sleep(1000); 

   // Close the door:  
   DeviceIoControl(hCdRom, IOCTL_STORAGE_LOAD_MEDIA, NULL, 0, NULL, 0, &dwBytes, NULL); 

   CloseHandle(hCdRom); 
}