Good afternoon and thank you for posting on the Final Fantasy XIV Technical Support Forums.

Do you receive any kind of error message when this happens? Does the game simply not respond or do you have to restart the entire PC?

When you reinstalled the game, did you delete the locally-saved data (located My Documents > My Games > Final Fantasy XIV)?

One thing you may want to try is a clean boot. Simply open the task manager and select the 'Start up' tab. Disable everything here and restart the PC. This will make sure that no background processes are interfering with the game.

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!