BOOL StateChange(DWORD NewState, DWORD SelectedItem,HDEVINFO hDevInfo)
{
    SP_PROPCHANGE_PARAMS PropChangeParams = 
{sizeof(SP_CLASSINSTALL_HEADER)};
    SP_DEVINFO_DATA DeviceInfoData = {sizeof(SP_DEVINFO_DATA)};
 
    //
    // Get a handle to the Selected Item.
    //
    if (!SetupDiEnumDeviceInfo(hDevInfo,SelectedItem,&DeviceInfoData))
        return FALSE;
 
    //
    // Set the PropChangeParams structure.
    //
    PropChangeParams.ClassInstallHeader.InstallFunction = 
DIF_PROPERTYCHANGE;
    PropChangeParams.Scope = DICS_FLAG_GLOBAL;
    PropChangeParams.StateChange = NewState; 
 
    if (!SetupDiSetClassInstallParams(hDevInfo,
        &DeviceInfoData,
        (SP_CLASSINSTALL_HEADER *)&PropChangeParams,
        sizeof(PropChangeParams)))
        return FALSE;
 
    //
    // Call the ClassInstaller and perform the change.
    //
    if (!SetupDiCallClassInstaller(DIF_PROPERTYCHANGE,
        hDevInfo,
        &DeviceInfoData))
        return FALSE;
 
    return TRUE;
}
 
BOOL DisableNetAdapter()
{
	HDEVINFO hdi;
	BOOL	 res;
 
    // get a list of all devices of class 'GUID_DEVCLASS_NET'
    hdi = SetupDiGetClassDevs(&GUID_DEVCLASS_NET, NULL, NULL, 
DIGCF_PRESENT);
	if (hdi == INVALID_HANDLE_VALUE)
		return FALSE;
 
	res = StateChange(DICS_DISABLE, 0, hdi);
 
	// release the device info list
	SetupDiDestroyDeviceInfoList(hdi);
 
	return res;
}
 
BOOL EnableNetAdapter()
{
	HDEVINFO hdi;
	BOOL	 res;
 
    // get a list of all devices of class 'GUID_DEVCLASS_NET'
    hdi = SetupDiGetClassDevs(&GUID_DEVCLASS_NET, NULL, NULL, 
DIGCF_PRESENT);
	if (hdi == INVALID_HANDLE_VALUE)
		return FALSE;
 
	res = StateChange(DICS_ENABLE, 0, hdi);
 
	// release the device info list
	SetupDiDestroyDeviceInfoList(hdi);
 
	return res;
}