I can't launch the game as well. It downloaded the update but never got to the login. It just pops up and closes immediately. Is this the same for you? I also killed my install folder and I wanted to try to install GW2 new, but I am having the exact same issue with the installer. I just see the 0kb download window and then it terminates the process without any errors or notifications.
-repair or -windowed option did nothing for me. process just gets terminated. I had the latest nvidia driver installed as well, but rolled back to also eliminate this cause