It is possible to apply to change status from tourist to student. Whether it would be approved or not depends upon several factors, including how long one was in the U.S. before applying for the change of status, what was said to the consular officer when applying for the visitor’s visa in the first place, and whether there is adequate financial support for school. An additional factor that is sometimes raised by the USCIS, but more often by consulates, is whether or not one has shown an intent to return to the home country. An individual who enters on a B-2 visa may not enroll and begin classes unless and until the application for change of status has been approved.
Please note that, if one travels abroad after the change-of-status application is approved, it would be necessary to obtain the F-1 visa at a U.S. consulate. It can be difficult to get the visa after having changed status, since the consular officer would question why one did not obtain the F-1 visa originally, instead of entering the U.S. as a B-2 visitor.
