Cуществует ли диск в системе?

Code:

function DriveExists (Drive: Byte) : boolean;

begin

Result := Boolean (GetLogicalDrives and (1 shl Drive));

end;

procedure TForm1.Button1Click(Sender : TObject);

var Drive : byte;

begin

for Drive := 0 to 25 do

If DriveExists (Drive) then

begin

ListBox1.Items.Add (Chr(Drive+$41));

end;

end;