Have you done basic troubleshooting such as restarting your computer?

Restart your machine. If that doesn't fix anything, I'd look at making sure Windows is up to date, and all your graphics and sound drivers are up to date.

You might try re-installing if you want; corrupted files after just recently installing would be rare, but if you have fast internet / don't care too much about the time factor, give it a shot.

Outside of that, if you Google the 'Unexpected Error' for FF14, there are tons and tons of reasons and solutions for the error. Are you getting any other text in the "Unexpected Error" box?