Geting SQL Server instances names from registry

Question

I have tried to get my SQLServer instances names from the registry by using this code:

type
  TRegistryHelper = class helper for TRegistry
  public
    function ReadMultiSz(const name: string; var Strings: TStrings): boolean;
  end;
    
function TRegistryHelper.ReadMultiSz(const name: string;
  var Strings: TStrings): boolean;
var
  iSizeInByte: integer;
  Buffer: array of WChar;
  iWCharsInBuffer: integer;
  z: integer;
  sString: string;
begin
  iSizeInByte := GetDataSize(name);
  if iSizeInByte > 0 then begin
    SetLength(Buffer, Floor(iSizeInByte / sizeof(WChar)));
    iWCharsInBuffer := Floor(ReadBinaryData(name, Buffer[0], iSizeInByte) / sizeof(WChar));
    sString := '';
    for z := 0 to iWCharsInBuffer do begin
      if Buffer[z] <> #0 then begin
        sString := sString + Buffer[z];
      end else begin
        if sString <> '' then begin
          Strings.Append(sString);
          sString := '';
        end;
      end;
    end;
    result := true;
  end else begin
    result := false;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
const
  cKey = '\SOFTWARE\Microsoft\Microsoft SQL Server';
var
  Registry: TRegistry;
  MyList: TStrings;
begin
  Registry := TRegistry.Create;
  Registry.RootKey := HKEY_LOCAL_MACHINE;
  if Registry.OpenKeyReadOnly(cKey) then
  try
    MyList := TStringList.Create();
    Registry.ReadMultiSz('InstalledInstances', MyList);
    ListBox1.Items.Assign(MyList);
  finally
    MyList.Free;
  end;
  Registry.Free;
end;

But I have noted the iSizeInByte = -1 every time, and I failed to get those names by this way.

Also, I have noted that when trying to get those instances from my TADOQuery connection string builder, the component also failed to get those names.

Is there any way to get them?