After having a clean boot crash my PC to the point of having to hard reset my main HD with the windows OS on it. Try this for I kept getting Dx11 errors from just 1 quest. Uninstall ff14 fully and do a clean reinstall. Mine worked and Im still salty at support for even suggesting the clean boot (and even my cousin that works for Microsoft is wondering why they said for it can cause a lot of issues like I just had)