How do I get the friendly name of a COM port in Windows?

Question

I have a GSM modem connected via USB. The modem creates 2 serial ports. The first is automatically attached to the modem, the second shows in Device Manager as \"HUAWEI Mo

Answer 1

Based off a combination of answer here is a solution that gets the COM number, VID / PID and friendly name etc.

Here is some example code for getting the list of connected devices.

public static class SerialPortUtils
{
    private static Guid GUID_DEVCLASS_PORTS = new Guid(0x4d36e978u, 0xe325, 0x11ce, 0xbf, 0xc1, 0x08, 0x00, 0x2b, 0xe1, 0x03, 0x18);

    private unsafe static bool GetPortRegistryProperty(HDEVINFO classHandle, SP_DEVINFO_DATA* deviceInfo, uint spdrp, out string result)
    {
        DWORD size;
        SetupAPI.SetupDiGetDeviceRegistryPropertyW(classHandle, deviceInfo, spdrp, null, null, 0, &size);
        if (size == 0)
        {
            result = null;
            return false;
        }

        var resultBuffer = new byte[(int)size];
        fixed (byte* resultBufferPtr = resultBuffer)
        {
            if (SetupAPI.SetupDiGetDeviceRegistryPropertyW(classHandle, deviceInfo, spdrp, null, resultBufferPtr, size, null))
            {
                result = Encoding.Unicode.GetString(resultBufferPtr, (int)size - sizeof(char));
                return true;
            }
            else
            {
                result = null;
                return false;
            }
        }
    }

    public unsafe static List GetSerialPortDevices()
    {
        var results = new List();

        // get present ports handle
        var classHandle = SetupAPI.SetupDiGetClassDevsW(ref GUID_DEVCLASS_PORTS, null, IntPtr.Zero, SetupAPI.DIGCF_PRESENT);
        if (classHandle == Common.INVALID_HANDLE_VALUE || classHandle == HDEVINFO.Zero) throw new Exception("SetupDiGetClassDevsW failed");

        // enumerate all ports
        var deviceInfo = new SP_DEVINFO_DATA();
        uint deviceInfoSize = (uint)Marshal.SizeOf();
        deviceInfo.cbSize = deviceInfoSize;
        uint index = 0;
        while (SetupAPI.SetupDiEnumDeviceInfo(classHandle, index, &deviceInfo))
        {
            // get port name
            string portName;
            HKEY regKey = SetupAPI.SetupDiOpenDevRegKey(classHandle, &deviceInfo, SetupAPI.DICS_FLAG_GLOBAL, 0, SetupAPI.DIREG_DEV, WinNT.KEY_READ);
            if (regKey == Common.INVALID_HANDLE_VALUE || regKey == IntPtr.Zero) continue;
            using (var regHandle = new SafeRegistryHandle(regKey, true))
            using (var key = RegistryKey.FromHandle(regHandle))
            {
                portName = key.GetValue("PortName") as string;
                if (string.IsNullOrEmpty(portName)) continue;
            }

            // get registry values
            if (!GetPortRegistryProperty(classHandle, &deviceInfo, SetupAPI.SPDRP_FRIENDLYNAME, out string friendlyName)) continue;
            if (!GetPortRegistryProperty(classHandle, &deviceInfo, SetupAPI.SPDRP_HARDWAREID, out string hardwareID)) continue;

            // add device
            results.Add(new SerialPortDeviceDesc(friendlyName, portName, hardwareID));

            // setup for next device
            ++index;
            deviceInfo = new SP_DEVINFO_DATA();
            deviceInfo.cbSize = deviceInfoSize;
        }

        // finish
        SetupAPI.SetupDiDestroyDeviceInfoList(classHandle);
        return results;
    }
}

Here is the SerialPortDeviceDesc class

public enum SerialPortType
{
    Unknown,
    COM
}

public class SerialPortDeviceDesc
{
    public readonly string friendlyName, portName, hardwareID;
    public readonly string vid, pid;
    public readonly int portNumber = -1;
    public readonly SerialPortType portType = SerialPortType.Unknown;

    public SerialPortDeviceDesc(string friendlyName, string portName, string hardwareID)
    {
        this.friendlyName = friendlyName;
        this.portName = portName;
        this.hardwareID = hardwareID;

        if (portName.StartsWith("COM") && int.TryParse(portName.Substring("COM".Length), out portNumber))
        {
            portType = SerialPortType.COM;
        }
        else
        {
            portNumber = -1;
        }

        var rx = Regex.Match(hardwareID, @"VID_(\w*)&PID_(\w*)", RegexOptions.IgnoreCase);
        if (rx.Success)
        {
            vid = rx.Groups[1].Value;
            pid = rx.Groups[2].Value;
        }
    }
}