Well. Finally, after a week waiting, my isp sent me another router (same mode, but new) and now it's all seted up correctly but I still have the same problem, BUT, now windows troubleshooter will fix my problem, the thing is, I have to run the troubleshooter everytime I turn on my pc. It says "IP does not have a valid configuration" and then fixes it. I mean... now I don't have to restart my pc, but now I have to run Windows Troubleshooter.