In 2016, the entrance window of the VTT spontaneously broke. After that, observations with the telescope were only possible to a very limited extent. Unfortunately, a temporarily procured entrance window did not have sufficient optical quality. At the beginning of 2022, the National Solar Observatory, Boulder USA, provided us with a used entrance window from their telescope. Since this window was larger than the one from the VTT, an adapter had to be made. With the help of the adapter, the window was successfully installed at the beginning of October (Thomas Sonner, Miguel Esteves, Marcel Kiefer). After the telescope was evacuated, observations with the adaptive optics wavefront sensor showed that the window was of good quality (Thomas Berkefeld).