Step 2 (females [AS PER AMENDMENT 11/13/00: opting to participate in Step 2]): At the onset of their second menstrual period (Cycle 2) since starting study, female patients start their choice of Ortho-Novum 1/35 or intramuscularly administered Depo-Provera [AS PER AMENDMENT 6/12/01: Enrollment for Depo-Provera is closed]. Contraceptive therapy continues throughout Step 2. Step 2 Days 0-6: Between days 7-11 [AS PER AMENDMENT 6/3/99: Between days 7-18] of the third menstrual cycle (Cycle 3) since starting study, female patients continue their pre-study antiretroviral therapy (as done in Step 1) and begin another course of ZDV standard therapy 3 times daily. Days 7-8: Patients receive the original method of administration of ZDV (as randomized at study entry). Female patients return for a final safety visit within 1 week of completing study Day 8 of Step 2.