Question:
How can I test and set the CD autorun option under 32 bit versions
of Windows?
Answer:
You can check the 4 byte value in the Windows registry under:
Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\
NoDriveTypeAutoRun
Setting the following bit numbers of the value of this key will
cause Windows not to use any auto run capabilities that may be
present for the device denoted by the bit number.
DRIVE_UNKNOWN = bit # 0
DRIVE_NO_ROOT_DIR = bit #1
DRIVE_REMOVABLE= Bit # 2
DRIVE_FIXED = Bit #3
DRIVE_REMOTE= Bit #4
DRIVE_CDROM= Bit #5
DRIVE_RAMDISK= Bit #6
You can also set this value to test the autorun capability of a
program you are developing from a floppy or network drive, by
setting the value to boot the autorun program from a floppy disk
(DRIVE_REMOVEABLE) or network drive (DRIVE_REMOTE). If the
device does not have auto-insert detection capabilities, simply
inserting the disk and pressing F-5 from the Windows explorer
should cause the autorun program to boot.
The following example demonstrates the ability to check if the
autorun detection of the CD is enabled, and also demonstrates
the ability of turning the autorun detection both on and off
for the CD.
Example
uses
Registry;
function IsCdAutoRunOn : bool;
var
reg: TRegistry;
AutoRunSetting : integer;
begin
reg := TRegistry.Create;
reg.RootKey := HKEY_CURRENT_USER;
reg.OpenKey(
'Software\Microsoft\Windows\CurrentVersion\Policies\Explorer',
false);
reg.ReadBinaryData('NoDriveTypeAutoRun',
AutoRunSetting ,
sizeof(AutoRunSetting));
reg.CloseKey;
reg.free;
result := not ((AutoRunSetting and (1 shl 5)) <> 0);
end;
procedure SetCdAutoRun(bOn : bool);
var
reg: TRegistry;
AutoRunSetting : integer;
begin
reg := TRegistry.Create;
reg.RootKey := HKEY_CURRENT_USER;
reg.LazyWrite := false;
reg.OpenKey(
'Software\Microsoft\Windows\CurrentVersion\Policies\Explorer',
false);
reg.ReadBinaryData('NoDriveTypeAutoRun',
AutoRunSetting ,
sizeof(AutoRunSetting));
if bOn then
AutoRunSetting := AutoRunSetting and not (1 shl 5)
else
AutoRunSetting := AutoRunSetting or (1 shl 5);
reg.WriteBinaryData('NoDriveTypeAutoRun',
AutoRunSetting ,
sizeof(AutoRunSetting));
reg.CloseKey;
reg.free;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
if IsCdAutoRunOn then
ShowMessage('CD AutoRun Is On') else
ShowMessage('CD AutoRun Is Off');
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
SetCdAutoRun(True);
end;
procedure TForm1.Button3Click(Sender: TObject);
begin
SetCdAutoRun(False);
end;