Patients in Group I begin study therapy within 7 to 14 days of screening. Patients are randomized to 1 of 2 treatment arms. Arm A receives stavudine (d4T) plus didanosine (ddI) plus ritonavir plus indinavir. Arm B receives d4T plus ddI plus ritonavir plus indinavir plus hydroxyurea. Patients are discontinued from hydroxyurea after Week 24. Group II consists of patients who meet eligibility criteria but who elect not to receive antiretroviral treatment. Patients in Groups I and II follow the same schedule of evaluations. Enrollment visit (Week 0) evaluations are completed prior to dispensing drugs, and all patients have clinical, virologic, and immunologic evaluations performed every 4 weeks through Week 24, then every 8 weeks thereafter. Patients in Group I take study drugs for 104 weeks with an optional 52-week rollover. Laboratory results from the Week 96 evaluation are used to decide whether or not patients continue on study medications. Patients who elect not to participate in the optional rollover or meet criteria for treatment failure at any time during the study are offered the best available treatment at the discretion of their HIV care provider and continue to be followed at 8-week intervals.