[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
private static extern SafeFileHandle CreateFile(string lpFileName,[MarshalAs(UnmanagedType.U4)] FileAccess dwDesiredAccess,
[MarshalAs(UnmanagedType.U4)] FileShare dwShareMode,
IntPtr lpSecurityAttributes,
[MarshalAs(UnmanagedType.U4)] FileMode dwCreationDisposition,
[MarshalAs(UnmanagedType.U4)] FileAttributes dwFlagsAndAttributes,
IntPtr hTemplateFile);

SafeFileHandle handle = CreateFile(lpFileName: @"\.C:",dwDesiredAccess: FileAccess.Read,dwShareMode: FileShare.ReadWrite,
lpSecurityAttributes: IntPtr.Zero,dwCreationDisposition: FileMode.OpenOrCreate,
dwFlagsAndAttributes: FileAttributes.Normal,hTemplateFile: IntPtr.Zero);

using (FileStream disk = new FileStream(handle, FileAccess.Read))
{
   byte[] mbrData = new byte[512];
   Console.WriteLine("Starting MBR Backup...");
   try
   {
     disk.Read(mbrData, 0, mbrData.Length);
     FileStream mbrSave = new FileStream("mbr.img", FileMode.Create);
     mbrSave.Write(mbrData, 0, mbrData.Length);
     Console.WriteLine("MBR Backuped to mymbr.img success!");
   }
   catch (Exception e)
   {
       Console.WriteLine(e.Message);
   }
}