The visa is a permit stamped inside your passport by an official of another country's consulate or embassy that enables you to enter that country. You must have a valid visa in your passport to enter the United States. A visa to enter the U.S. is only issued at a U.S. consulate outside of the United States. There is no way to obtain or renew a visa stamp in your passport while in the United States. Students must travel to their home country, Canada or Mexico to apply for and receive a visa. The most common type of visa issued for study in the U.S. is the F-1 visa.

Continuing Student - What is needed to renew my visa?

To renew your F-1 visa, you will need to submit the following documents to a U.S. Embassy or Consulate:
1 Visa application forms -  DS 160 (Application for Nonimmigrant Visa), DS 157 (Supplemental Nonimmigrant Visa Application) and DS 158 (Contact Information and Work History for Nonimmigrant Visa Applicant)
2 Valid passport that does not expire for at least six months
3 Current SEVIS I-20 with immigration adviser's signature
4 Enrollment Letter - Proof of enrollment from Office of the Registrar
5 Copy of current WTAMU transcript
6 Proof of financial support
7 Proof of ties to your home country
8 Passport size photo
9Things to Remember When Applying for a Visa
Note: Re-entry to the U.S. may be denied if your F-1 visa has expired. Security checks may delay issuance for several weeks.