How can I use innosetup to automatically download files from Microsoft

I am using the UseroSetup Tools Downloader plugin here . It allows you to download external internet files during installation. While it may work in many cases, in some cases:

itd_addfile('http://download.microsoft.com/download/1/d/b/1dbee406-9b5f-48c5-b901-dd1a3f3c4669/Merlin.exe',expandconstant('{tmp}\Merlin.exe'));

      

        
        
        
      

    

He complains about the following:

Sorry, files cannot be downloaded. Check the connection and click Retry to upload the files again or click Cancel to complete the setup.

We can use a web browser to open and download:

http://download.microsoft.com/download/1/d/b/1dbee406-9b5f-48c5-b901-dd1a3f3c4669/Merlin.exe

      

        
        
        
      

    

Why can't it be automatically downloaded by itdownload?
How to fix it?

Below is a modified example1 that caused the problem.

#define MyAppName "My Program"
#define MyAppVerName "My Program 1.5"
#define MyAppPublisher "My Company, Inc."
#define MyAppURL "http://www.mycompany.com"

[Setup]
AppName={#MyAppName}
AppVerName={#MyAppVerName}
AppPublisher={#MyAppPublisher}
AppPublisherURL={#MyAppURL}
AppSupportURL={#MyAppURL}
AppUpdatesURL={#MyAppURL}
DefaultDirName={pf}\{#MyAppName}
DefaultGroupName={#MyAppName}
OutputBaseFilename=example1
Compression=lzma
SolidCompression=true
CreateAppDir=true
ShowLanguageDialog=yes

[Languages]
Name: english; MessagesFile: compiler:Default.isl

#include ReadReg(HKEY_LOCAL_MACHINE,'Software\Sherlock Software\InnoTools\Downloader','ScriptPath','');

[Code]
procedure InitializeWizard();
begin
 itd_init;

 //Let download two zipfiles from MS Agent  website..
 itd_addfile('http://download.microsoft.com/download/1/d/b/1dbee406-9b5f-48c5-b901-dd1a3f3c4669/Merlin.exe',expandconstant('{tmp}\Merlin.exe'));

 //Start the download after the "Ready to install" screen is shown
 itd_downloadafter(wpReady);
end;

procedure CurStepChanged(CurStep: TSetupStep);
begin
 if CurStep=ssInstall then begin //Lets install those files that were downloaded for us
  filecopy(expandconstant('{tmp}\Merlin.exe'),expandconstant('{app}\Merlin.exe'),false);
 end;
end;