So because there will be another beta I wanted to redownload the game but i noticed that I have a folder called The elder scrolls online which is 29,4 GB. There are three folders inside it and I can start the game from game/client/eso.exe but I don't have my launcher anymore so I can't update. Are there any way I can update without download the whole game again?

Try to download again since all u do download is the installer for the launcher, but also remember that the beta forums are open now and ao is their tech help forum