Change of Status
You may change from one non-immigrant status to another non-immigrant status without leaving the country. If you entered the country on a B-2 (visitor’s) visa and wish to change to F-1, you must wait until your change has been approved before you may begin classes. A change of status from B-2 to F-1 is not automatic and may be denied. The U.S. Department of Homeland Security: Study in the States website offers more Change of Status information.