In case anyone else ventured into this thread after recent betas, I had simillar problem with launcher on Windows. It showed up, then dissapeared. After uninstalling the game, fresh installator also showed up, downloaded some files, unpacked them in launcher floder, then crashed and stayed as a background process.
Solution that worked for me was just turning off the antivirus (till the login screen apppeared) and launching the installer in admin mode (not sure which one helped).