I recently purchased a new computer and have been plagued with constant crash issues. It used to be that I couldnt last 2 hours without a crash that would completely lock up my computer. I was in the process of filling out a support ticket when a pop up from Anet came on my screen with a suggestion. I dont know why this is not more common knowledge... hours of searching the forums for a fix and this is the first I have seen it. After doing this fix I have ran GW2 for 2 days without a crash! A Record! So if you find yourself in a similar situation, try this quick and easy fix.
1. Go to your main guild wars file. Mine was at "c:/Program Files (x86)/Guild Wars 2/gw2.exe"
2. Right click on GW2.exe and create a shortcut on your desktop.
3. Go to your desktop and rename that file "Guild Wars 2 Repair"
4. Right click on that icon and click Properties. Where it says TARGET add the word "-repair" at the end of the line. Mine looked like this afterwards.
"C:\Program Files (x86)\Guild Wars 2\Gw2.exe" -repair
Make sure -repair is OUTSIDE the quotation.
5. Once you have done that open that file and allow it to do its work. I had to download 8 files.
As far as I can tell it searches thru your GW2 file and seeks out any possible missing or corrupted files and repairs them.
How this is not a sticky in the Tech Support forum at guildwars2.com baffles me.