The purpose of this study is to compare two different anti-HIV drug combinations, one that contains nelfinavir (NFV) and one that does not. The best dosing schedule for indinavir (IDV) also will be studied.

Patients are stratified by screening plasma viral RNA results (50,000 copies/ml or below vs above 50,000 copies/ml) and randomized to 1 of 2 treatment arms. Group 1 receives IDV 3 times daily plus d4T/3TC twice daily. Group 2 receives IDV/NFV/d4T/3TC twice daily. Patients remain on study medications for 24 weeks and are seen at the clinic once every 4 weeks after entering the study. At each clinic visit, blood samples are taken to evaluate CD4 cell count and plasma HIV RNA levels.

Inclusion Criteria

You may be eligible for this study if you:

• Are HIV positive.
• Have a viral load (level of HIV in your blood) of at least 10,000 copies/ml within 45 days of study entry.
• Have a CD4 cell count of at least 100 cells/mm3 within 45 days of study entry.
• Have a normal chest X-ray.
• Have never taken protease inhibitors or 3TC.
• Are 16 years of age or older.
• Agree to practice sexual abstinence or use barrier methods of birth control (e.g., condoms).

Exclusion Criteria

You will not be eligible for this study if you:

• Have an active opportunistic (AIDS-related) infection or cancer.
• Have certain types of Kaposi's sarcoma.
• Have hepatitis.
• Have chronic diarrhea.
• Have a history of certain medical conditions.
• Are allergic to any of the study medications.
• Are taking certain medications.
• Are pregnant or breast-feeding.