C#操作并口时报错？？

        public const short FILE_ATTRIBUTE_NORMAL = 0x80;
    public const short INVALID_HANDLE_VALUE = -1;
    public const uint GENERIC_READ = 0x80000000;
    public const uint GENERIC_WRITE = 0x40000000;
    public const uint CREATE_NEW = 1;
    public const uint CREATE_ALWAYS = 2;
    public const uint OPEN_EXISTING = 3;

    [DllImport("kernel32.dll", SetLastError = true)]
    static extern IntPtr CreateFile(string lpFileName, uint dwDesiredAccess,
        uint dwShareMode, IntPtr lpSecurityAttributes, uint dwCreationDisposition,
        uint dwFlagsAndAttributes, IntPtr hTemplateFile);
    public string SendCMDToLPT1()
    {
        try
        {
            IntPtr ptr = CreateFile("LPT1", GENERIC_WRITE, 0,
                     IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero);
            if (ptr.ToInt32() == -1)
            {
                Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
            }
            else
            {
                FileStream lpt = new FileStream(ptr, FileAccess.ReadWrite);
                Byte[] buffer = new Byte[5];
                //0x1B， 0x70， 0x00，0x16,0x16
                buffer[0] = 0x1B;
                buffer[1] = 0x70;
                buffer[2] = 0x00;
                buffer[3] = 0x16;
                buffer[4] = 0x16;
                lpt.Write(buffer, 0, buffer.Length);
                lpt.Close();
            }
            return "";
        }
        catch (Exception e)
        {
            return "" + e.Message.ToString();
        }
    }

            以上是我操作并口的代码。在winform工程下这个是很好用的。
            后来封装到ActiveX，里面。用IE调用的时候。
            IntPtr ptr = CreateFile("LPT1", GENERIC_WRITE, 0,
                     IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero);

            运行到这个句话的时候异常。

            请教各位大侠！

权限不足，ActiveX没有操作lpt1的权限，lpt1相当于文件，需要给浏览器提权，还要设置安全等级为低才行。

先查看错误信息，是否为权限问题，IE运行在保护模式下，权限比较低，很多目录，设备等都不能访问

把所有的安全提示都关了