Patients take IDV plus RTV plus d4T plus 3TC twice daily for 24 weeks. Every 4 weeks, patients have physical exams and laboratory tests of blood and urine, and CD4 cell counts and plasma viral RNA are measured. At Week 24, the proportion of patients with plasma viral RNA below 400 copies/ml is determined to identify any clinically meaningful antiretroviral activity for the drug regimen. An observed response proportion of 80% or higher will be considered clinically meaningful.