Guild Wars 2

Hello Everyone!
I haven’t logged onto GW2 in a while, but decided to play again today because of the expansion coming out soon. Anyways, I played maybe 10 minutes before I had to log off.

I came back a while later clicked the GW2 icon, entered username + password, pressed play, and… nothing, it closed the launcher, but no new window opened, nothing.

I tried my other account, still nothing. I even uninstalled and reinstalled, still doesn’t work. No crash message, no not responding message.

Huh, so I figured out how to get it to run, I had to make it run on my integrated graphics card as opposed to my nvidia Geforce, which sucks because now it gets lesser performance.
Why did it run on Nvidia before, but not now?