Patients are randomized to 1 of 2 treatment arms. One arm is treated with GW433908/RTV plus ABC and 3TC. The other is treated with NFV plus ABC and 3TC. Each group is treated for 48 weeks. The following are compared in the 2 arms: 1) magnitude and durability of antiviral response; 2) safety, tolerance, and antiviral response after 24 and 48 weeks of therapy; 3) time to treatment failure; 4) immunologic response; 5) occurrence of events related to metabolic abnormalities; and 6) development of viral resistance in a subset of patients following treatment. Also studied are: 1) steady-state plasma drug trough concentrations; 2) demographic, virologic, immunologic, pharmacologic, and adherence factors that may be associated with treatment outcome; 3) patient adherence to the drug regimens; 4) study medication utilization; and 5) resource utilization.