In this double-blind, placebo-controlled, pediatric study, 210 patients are randomized to receive 2 NRTIs plus either 141W94 or placebo. Enrollment of patients is sequential: patients 13 to 18 years of age are enrolled first, followed by children < 13 when the appropriate pediatric dose has been determined. Patients who are unable to swallow capsules will be accrued when a liquid formulation becomes available.