For me was solution to do this:
1. Navigate to your Guild Wars 2 installation folder.
2. Right-click on “GW2.exe” and select “Create Shortcut.”
3. Rename this shortcut to “anything you want”.
4. Right-click on this shortcut and select “Properties”.
5. Edit the “Target” line to include /clientport 80 at the end.
Note: Please make sure /clientport 80 is outside of the quotes
Correctly Formatted Example: “C:\Games\Guild Wars 2\GW2.exe” /clientport 80
Incorrectly Formatted Example: “C:\Games\Guild Wars 2\GW2.exe /clientport 80”
6. Set run compatible for: Windows Vista (Service Pack 2).
7. Set run as administrator .
8. Once completed, click “Ok” to save your changes.
If you get an error trying to save, your target line may not have the correct format. Please try step 5 again.
9. Run by created shortcut .
In steps 6. and 7. I am not sure of right labels, cause I have other language version of win7 x64.
Hope it helps others!