Traverse system hardware device information

The following code snippet shows how to display a list Of all installed hardware devices:

#include <stdio.h>#include <windows.h>#include <setupapi.h>#include <devguid.h>#include <regstr.h>int main( int argc, char *argv[ ], char *envp[ ] ){    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         // to Alloc the buffer. Keep calling until        // success or an unknown failure.        //         while (!SetupDiGetDeviceRegistryProperty(            hDevInfo,            &DeviceInfoData,            SPDRP_DEVICEDESC,            &DataT,            (PBYTE)buffer,            buffersize,            &buffersize))        {            if (GetLastError() ==                 ERROR_INSUFFICIENT_BUFFER)            {                // Change the buffer size.                if (buffer) LocalFree(buffer);                buffer = LocalAlloc(LPTR,buffersize);            }            else            {                // Insert error handling here.                break;            }        }                printf("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;}

The following code snippet shows how to retrieve all display adapter groups on the system:

    hDevInfo = SetupDiGetClassDevs(        (LPGUID) &GUID_DEVCLASS_DISPLAY,        0,        0,        DIGCF_PRESENT);

The following code snippet shows how to retrieve all device groups on the Peripheral Component Interconnect (PCI) bus:

    hDevInfo = SetupDiGetClassDevs(NULL,        REGSTR_KEY_PCIENUM, // Enumerator        0,        DIGCF_PRESENT | DIGCF_ALLCLASSES );

The Windows API function that requires the device instance handle (such as the Config Manager group of the API function) to useSetupDiEnumDeviceInfoThe value of DevInst in the SP_DEVINFO_DATA structure returned by the function.