Neither , but I ended up restoring my computer to a long (!) before and then I was able to delete that file.
Then I ended up with a 5385 error problem for an "old launcher" I'm not sure but eventually this might have been the problem all along because everything seems to run smoothly now.
Atm redownloading the game (currently 11%) hope everything's going to be fine.
Thank you for your interest. :)