Guild Wars 2

hello i’ve this problem since yesterday gw2 dont want start is stuck at 0 and 0 on downloading patch

i’ve downgraded my system from a gtx 560 ti to a 9500gt 1gb ddr2 for few days but i t wont start

my pc is

asrock z77 pro4-m
8gb ram
cpu pentium g2020
vga 9500gt 1gb ddr2

I have the same problem too