代码:
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
iniFile : TStrings ;
begin
CreateDir('C:\YourFolder') ;
iniFile := TStringList.Create;
with iniFile do
begin
Add('[.ShellClassInfo]') ;

Add('IconFile = ' + GetEnvironmentVariable('Windir')
+ '\system32\SHELL32.DLL') ;

Add('IconIndex = 38') ;


Add('InfoTip = This is folder with icon') ;
SaveToFile('C:\YourFolder\Desktop.ini');
end;

SysUtils.FileSetAttr('C:\YourFolder', SysUtils.faReadOnly) ;
SysUtils.FileSetAttr('C:\YourFolder\Desktop.ini',
SysUtils.faSysFile or SysUtils.faHidden) ;
iniFile.Free ;
end;

end.

里面的YourFolder可以自己改文件夹的名称