I managed to do it once, but with a different computer than the one i have now (the previous one broke down) and after the change, i don't know why i could never do it again. Perhaps some important configuration has been changed in the router interface or in my local area connection (such as static / dynamic IP or something like that). I really don't know the exact reason why it happened.

Thanks for read me and for your time. Please help me, i tried different ways to fix it but nothing worked and now i don't know what to do.