Ok, after some code changes, I tried the following lines: Window window = _dte2.Windows.Item(captionOfToolWindow); window.Activate(); window.Visible = true; but I still get an error: "Value does not fall within the expected range." The funny thing is, that as long as the toolwindow was not closed, the method works fine (the toolwindow is activated). How can I avoid that the toolwindow is taken out of the Windows collection?! Anyone?!
