Hi hi,

a bluescreen while trying to update ffxiv can have multiple reasons, which don't have to be caused by ffxiv in particular.
The best way to help you is having the informations the bluescreen is containing *error code+parameters at best)
I used to have the problem that my PC would crash entirely as soon as i started ffxiv, turned out to be a mainboard issue, aka unrelated to the game itself, but only happening with the game and nowhere else.