#include <stdio.h>

#include <windows.h>

#include <setupapi.h>

#include <devguid.h>

#include <regstr.h>

#include <tchar.h>


#pragma comment(lib, "setupapi.lib")


int main(int argc, char *argv[])
{
  HDEVINFO hDevInfo;
  SP_DEVINFO_DATA DeviceInfoData;
  DWORD i;

  // Create a HDEVINFO with all present devices.
  hDevInfo = SetupDiGetClassDevs(NULL,
                                 0, // Enumerator
                                 0,
                                 DIGCF_PRESENT | DIGCF_ALLCLASSES);
  
  if (hDevInfo == INVALID_HANDLE_VALUE) {
    // Insert error handling here.
    return 1;
  }
       
  // Enumerate through all devices in Set.
  DeviceInfoData.cbSize = sizeof(SP_DEVINFO_DATA);
  for (i = 0; SetupDiEnumDeviceInfo(hDevInfo, i, &DeviceInfoData); i++) {
    DWORD DataT;
    LPTSTR buffer = NULL;
    DWORD buffersize = 0;
           
    //
    // Call function with null to begin with, 
    // then use the returned buffer size (doubled)
    // to Alloc the buffer. Keep calling until
    // success or an unknown failure.
    //
    //  Double the returned buffersize to correct
    //  for underlying legacy CM functions that 
    //  return an incorrect buffersize value on 
    //  DBCS/MBCS systems.
    // 
    while (!SetupDiGetDeviceRegistryProperty(hDevInfo,
                                             &DeviceInfoData,
                                             SPDRP_DEVICEDESC,
                                             &DataT,
                                             (PBYTE)buffer,
                                             buffersize,
                                             &buffersize)) {
      if (GetLastError() ==  ERROR_INSUFFICIENT_BUFFER) {
        // Change the buffer size.
        if (buffer) LocalFree(buffer);
        // Double the size to avoid problems on 
        // W2k MBCS systems per KB 888609. 
        buffer = (LPTSTR)LocalAlloc(LPTR,buffersize * 2);
      } else {
        // Insert error handling here.
        break;
      }
    }
           
    _tprintf(TEXT("Result:[%s]\n"), buffer);
           
    if (buffer) LocalFree(buffer);
  }
       
       
  if (GetLastError() != NO_ERROR &&
      GetLastError() != ERROR_NO_MORE_ITEMS) {
    // Insert error handling here.
    return 1;
  }
       
  //  Cleanup
  SetupDiDestroyDeviceInfoList(hDevInfo);

  return 0;
}