Modem & Router problem

So i've got another problem after swappin in my motherboard it actually worked... At my friend that is. Now i'm at home ones again and ITS NOT WORKING. Tried my "new" router that i recived from Felia (Telia), Thomson TG787 which i can actually use on my computer (Win7) but not my parents computer. Thought the weard thing is. I can access WoW online but not the web via my webbrowser. but after approx 5 min i cant play wow either. And on my parents side they cant do a shit. But swapping to the modem ZyXEL P-660H-D1, My parents computer is working (Win Vista) but mine wont work. No, I have not tried different cables in this case since i tried it when i changed my motherboard and my parents cable are working just fine when connected via the modem so it cant be any of em.

Anybody have a clue of what the problem might be? And FYI i have tried to restart the modem and it didnt work and the router wont even respond when im trying to restart it to the manifactureres default options.

Turn off the computer, unplug the power from the router, unplug power from modem and remove battery if it has one, this is only way to make the modem hard boot. After five minutes, re-install battery and connect power to the modem, when all the lights are on the modem, connect the router with no other connected cables to the modem. When all the router lights have come on connect the computer to the router, then boot the computer and check the status of the local area connection. Make sure all computers on your network have the same Workgroup name, i.e. workgroup, home1, mynethome...