Patients are randomized to receive 1 of 2 doses of IDV/RTV for 24 weeks (Arms A and B). All patients also receive 2 nucleoside reverse transcriptase inhibitors (NRTIs). The NRTIs are not provided by the study. Clinical assessments take place at Weeks 1, 2, 4, 8, 12, 16, 20, and 24 which includes a virology assessment. [AS PER AMENDMENT 4/21/00: Patients who experience a confirmed virologic failure (defined in protocol) and elect to remain on study treatment, are followed through Week 24. Patients who experience a confirmed virologic failure and elect to discontinue study treatment will have a final evaluation at the time of treatment discontinuation.] Patients are hospitalized for 12 hours at the Week 2 study visit for an intensive pharmacokinetic analysis.