A few people have mailed in that they are unable to use the Final Fantasy XIV free trial because the launcher does not display a “create account” button. Luckily, user Treyu86 over at the MMORPG.com forums figured out how to get the button to show. All you have to do is delete the Final Fantasy XIV folder listed in C:/Users/”username”/My Documents/My Games.
Deleting that folder will cause the client to recognize you as a new user, and allow you to create an account. You have to create the account through the FFXIV trial client.