Перечислить ключи реестра

{ 
  This example demonstrates how to enumerate all registry keys from 
  a certain key (here: HKEY_CURRENT_USER) 
}

uses
  Registry;

procedure TForm1.Button1Click(Sender: TObject);
var
  indent: Integer;

     procedure EnumAllKeys(hkey: THandle);
  var
    l: TStringList;
    n: Integer;
  begin
    Inc(indent, 2);
    with TRegistry.Create do
      try
        RootKey := hkey;
        OpenKey(EmptyStr, False);
        l := TStringList.Create;
        try
          GetKeynames(l);
          CloseKey;
          for n := 0 to l.Count - 1 do
          begin
            memo1.Lines.Add(StringOfChar(' ', indent) + l[n]);
            if OpenKey(l[n], False) then
            begin
              EnumAllKeys(CurrentKey);
              CloseKey;
            end;
          end;
        finally
          l.Free
        end;
      finally
        Free;
      end;
    Dec(indent, 2);
  end;

begin
  Memo1.Clear;
  Memo1.Lines.Add('Keys under HKEY_CURRENT_USER');
  indent := 0;
  Memo1.Lines.BeginUpdate;
  try
    EnumAllKEys(HKEY_CURRENT_USER);
  finally
    Memo1.Lines.EndUpdate;
  end;
end;