No internet out of sudden

The net went down suddenly . I had few sites opened , wanted to open one more I usually open , but it didnt open . Also google.com didnt open . I restarted my pc but it didnt help .
I have green led on Power , wireless , Ethernet , dsl
No green led on Internet .
I reset settings , powered off and on router , reinstalled whole win Xp , upgraded with new firmaware . I checked IP and DNS so it's ok to my Net provider in Poland .
Nothing works .
I tried to install router step by step , but it stops at trying to check gateway:
"Installation creator cant localize the gateway in net , cjheck if your hardware is powered on and if all the cables are fine "
(I have this alert in polish , I tried to translate it as best I can)
Please help :(