Автор: http://www.swissdelphicenter.ch

procedure TForm1.SetCDAutoRun(AAutoRun: Boolean);
 const
   DoAutoRun: array[Boolean] of Integer = (0, 1);
 var
   Reg: TRegistry;
 begin
   try
     Reg := TRegistry.Create;
     Reg.RootKey := HKEY_LOCAL_MACHINE;
     if Reg.KeyExists('System\CurrentControlSet\Services\Class\CDROM') then
     begin
       if Reg.OpenKey('System\CurrentControlSet\Services\Class\CDROM', False) then
         Reg.WriteBinaryData('AutoRun', DoAutoRun[AAutoRun], 1);
     end
   finally
     Reg.Free;
   end;
   ShowMessage('Your settings will take effect on the next reboot of Windows.');
 end;