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

Can you explain what exactly happens when you alt-tab out? You said it freezes but do you mean a crash or is the game just unresponsive? About how ling does it take to return to normal (if at all)?

Does the same thing happen in windowed mode?

When did this start happening? Did anything change/update on your PC that coincides with this?

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