To renew visa(F1), go to El-Paso(Mexico near TX) or Canada. But, it was easy before 9-11. Now, they changed rules. If you don't get visa there, you have to go back Nepal from there. You can not reenter U.S. from there. So, make sure everything(documents) before go there. If you don't apply for visa, then you can go there (either Canada or MX) for 30 days and can reenter U.S. only showing your I-94 and I-20(Valid) on the boarder. And be careful across the U.S. boarder!