public static void DeviceAudit()
        {
            var file = new FileStream("DeviceAudit.txt", FileMode.Create, FileAccess.Write);
            var sw = new StreamWriter(file);

            var keyboardNumber = 0;
            uint deviceCount = 0;
            var dwSize = (Marshal.SizeOf(typeof(Rawinputdevicelist)));

            if (GetRawInputDeviceList(IntPtr.Zero, ref deviceCount, (uint)dwSize) == 0)
            {
                var pRawInputDeviceList = Marshal.AllocHGlobal((int)(dwSize * deviceCount));
                GetRawInputDeviceList(pRawInputDeviceList, ref deviceCount, (uint)dwSize);

                for (var i = 0; i < deviceCount; i++)
                {
                    uint pcbSize = 0;

                    // On Window 8 64bit when compiling against .Net > 3.5 using .ToInt32 you will generate an arithmetic overflow. Leave as it is for 32bit/64bit applications
                    var rid = (Rawinputdevicelist)Marshal.PtrToStructure(new IntPtr((pRawInputDeviceList.ToInt64() + (dwSize * i))), typeof(Rawinputdevicelist));

                    GetRawInputDeviceInfo(rid.hDevice, RawInputDeviceInfo.RIDI_DEVICENAME, IntPtr.Zero, ref pcbSize);

                    if (pcbSize <= 0)
                    {
                        sw.WriteLine("pcbSize: " + pcbSize);
                        sw.WriteLine(Marshal.GetLastWin32Error());
                        return;
                    }

                    var size = (uint)Marshal.SizeOf(typeof(DeviceInfo));
                    var di = new DeviceInfo {Size = Marshal.SizeOf(typeof (DeviceInfo))};

                    if (GetRawInputDeviceInfo(rid.hDevice, (uint) RawInputDeviceInfo.RIDI_DEVICEINFO, ref di, ref size) <= 0)
                    {
                        sw.WriteLine(Marshal.GetLastWin32Error());
                        return;
                    }

                    var pData = Marshal.AllocHGlobal((int)pcbSize);
                    GetRawInputDeviceInfo(rid.hDevice, RawInputDeviceInfo.RIDI_DEVICENAME, pData, ref pcbSize);
                    var deviceName = Marshal.PtrToStringAnsi(pData);

                    if (rid.dwType == DeviceType.RimTypekeyboard || rid.dwType == DeviceType.RimTypeHid)
                    {
                        var deviceDesc = GetDeviceDescription(deviceName);

                        var dInfo = new KeyPressEvent
                        {
                            DeviceName = Marshal.PtrToStringAnsi(pData),
                            DeviceHandle = rid.hDevice,
                            DeviceType = GetDeviceType(rid.dwType),
                            Name = deviceDesc,
                            Source = keyboardNumber++.ToString(CultureInfo.InvariantCulture)
                        };

                        sw.WriteLine(dInfo.ToString());
                        sw.WriteLine(di.ToString());
                        sw.WriteLine(di.KeyboardInfo.ToString());
                        sw.WriteLine(di.HIDInfo.ToString());
                        //sw.WriteLine(di.MouseInfo.ToString());
                        sw.WriteLine("=========================================================================================================");
                    }

                    Marshal.FreeHGlobal(pData);
                }

                Marshal.FreeHGlobal(pRawInputDeviceList);

                sw.Flush();
                sw.Close();
                file.Close();

                return;
            }

            throw new Win32Exception(Marshal.GetLastWin32Error());
        }
 private static extern uint GetRawInputDeviceInfo(IntPtr hDevice, uint command, ref DeviceInfo data, ref uint dataSize);