BSOD is almost always hardware related, I would rule out Guild Wars 2 being the cause.
I would check your RAM first. Depending on what configuration you are running and what kind of interleaving your board supports, try and remove half of your RAM. If it still BSOD's, try the other half.
If that doesn't work, start looking at your remaining hardware.
Driver conflicts can also cause BSOD's on occasion, look for any obvious driver issues or conflicts in your device manager.