Author: William Gerbert 

How to disable the CD autorun feature through code

Answer:

Solve 1:

1   uses
2     Registry;
3   
4   function IsCdAutoRunOn: bool;
5   var
6     reg: TRegistry;
7     AutoRunSetting: integer;
8   begin
9     reg := TRegistry.Create;
10    reg.RootKey := HKEY_CURRENT_USER;
11    reg.OpenKey('Software\Microsoft\Windows\' + 'CurrentVersion\Policies\Explorer',
12      false);
13    reg.ReadBinaryData('NoDriveTypeAutoRun', +AutoRunSetting, sizeof(AutoRunSetting));
14    reg.CloseKey;
15    reg.free;
16    result := not ((AutoRunSetting and (1 shl 5)) <> 0);
17  end;
18  
19  procedure SetCdAutoRun(bOn: bool);
20  var
21    reg: TRegistry;
22    AutoRunSetting: integer;
23  begin
24    reg := TRegistry.Create;
25    reg.RootKey := HKEY_CURRENT_USER;
26    reg.LazyWrite := false;
27    reg.OpenKey('Software\Microsoft\Windows\' + 'CurrentVersion\Policies\Explorer',
28      false);
29    reg.ReadBinaryData('NoDriveTypeAutoRun', +AutoRunSetting, sizeof(AutoRunSetting));
30    if bOn then
31      AutoRunSetting := AutoRunSetting and not (1 shl 5)
32    else
33      AutoRunSetting := AutoRunSetting or (1 shl 5);
34    reg.WriteBinaryData('NoDriveTypeAutoRun', +AutoRunSetting, 
35  sizeof(AutoRunSetting));
36    reg.CloseKey;
37    reg.free;
38  end;



Solve 2:

After an hour of tinkering with some samples on the Internet I came up with the 
proper registry setting to turn on/off the CDROM AutoRun feature. The first thing 
wrong with all the samples was the type of value we need to store in the registry, 
I found that binary is what works. The next thing most samples neglected to say, 
besides being just wrong, was that you need to reboot your system after making the 
change. This tip was tested on Windows98, so this registry setting may differ a 
little for other operating systems. We will be using the TRegistry object using 
TRegistry.KeyExists, TRegistry.OpenKey, and TRegistry.WriteBinaryData

First we will need to add Registry to our unit's uses clause
Next we will need a TButton and a TButton.OnClick event. You can easily create this 
event through the Object Inspector Events tab
We will then declare a new procedure that will make the settings according to the 
boolean parameter sent in
In our routine we will first create our TRegistry object, then we will set the 
TRegistry.RootKey. Next we will check to see if the CDROM registry key exists 
before trying to open it. After opening the CDROM registry key we will add AutoRun 
to it according to the boolean parameter sent into the procedure
TRegistry.KeyExists returns TRUE is the specified registry key exists. The only 
parameter is a string to the key in the registry. If we set TRegistry.RootKey then 
we do not have to specify it within the string parameter
TRegistry.OpenKey returns TRUE if the specified registry key opens successfully. 
The first parameter is a string to the key in the registry. As mentioned above, if 
we set TRegistry.RootKey then we do not have to specify it within the string 
parameter. The second parameter is a boolean value telling Windows whether or not 
to create the key if it does not exist, we will set this to FALSE
TRegistry.WriteBinaryData stores binary data to the registry. The first parameter 
is the name to stoe under the open registry key. The second parameter is the value 
to store. The last parameter is the size of the binary value we are storing


39  {...}
40  
41  type
42    TForm1 = class(TForm)
43      Button1: TButton;
44      procedure Button1Click(Sender: TObject);
45    private
46      { Private declarations }
47      procedure SetCDAutoRun(AAutoRun: Boolean);
48    public
49      { Public declarations }
50    end;
51  
52    {...}
53  
54  procedure TForm1.Button1Click(Sender: TObject);
55  begin
56    SetCDAutoRun(FALSE);
57  end;
58  
59  procedure TForm1.SetCDAutoRun(AAutoRun: Boolean);
60  const
61    DoAutoRun: array[Boolean] of Integer = (0, 1);
62  var
63    Reg: TRegistry;
64  begin
65    try
66      { create our registry object }
67      Reg := TRegistry.Create;
68      { set our registry root key }
69      Reg.RootKey := HKEY_LOCAL_MACHINE;
70      { verify that our CDROM class key exists }
71      if Reg.KeyExists('System\CurrentControlSet\Services\Class\CDROM') then
72        { try to open our CDROM class key }
73        if Reg.OpenKey('System\CurrentControlSet\Services\Class\CDROM', FALSE) then
74          { add AutoRun to our CDROM class key }
75          Reg.WriteBinaryData('AutoRun', DoAutoRun[AAutoRun], 1);
76    finally
77      { free our registry object }
78      Reg.Free;
79    end;
80    { showmessage that the changes will happen on reboot }
81    ShowMessage('Your settings will take effect on the next reboot of Windows.');
82  end;
83  
84  {...}