The B-2 visa (Tourist Visa) is not considered a student visa for full-time study. Studying in the US on a B-2 visa is grounds for deportation. Switching from a B-2 visa to a F-1 or J-1 visa after arriving in the US is extremely difficult, and may be grounds for deportation or prosecution for visa fraud. If you intend to enter the US with a B-2 visa and possibly switch later to a F-1 or J-1 visa, be sure to get the visa with a "Prospective Student" stamp on it. You'll probably need to supply a copy of a letter of admission before they will grant you a B-2 visa with a "Prospective Student" stamp on it. As a general rule, if you intend to enter the US as a student, you should get a F-1 or J-1 visa. If you decide to change status after arriving in the US, you should wait at least 60 days to avoid presumptions of visa fraud.