I believe I have a solution!
I’m not 100% sure this will fix your specific problem, but for me it worked.
For a few weeks now my Guild Wars 2 has been having similar issues as listed by the people before me. It would instantly crash my entire computer upon loading up the game.
So my solution (Note this is what worked for me, not necessarily will work for you)
1) Open the launcher and remove the auto-start feature (if you haven’t already)
2) Open Steam and add Gw2 as a non-steam game
3) Open Gw2 from Steam and login, then press Play.
This worked for me, let me know if this will work for you as well.