Prior ACTG studies have shown that the 3-drug combination regimen (IDV/ZDV/3TC) resulted in improved clinical outcomes and therefore may prolong the effects of therapy. The enhanced effects seen with combination therapies are likely related to a greater suppression of RNA replication and alterations in resistance patterns. Due to the progressive success of combination regimens, it is possible that more potent regimens will further enhance viral suppression and provide more durable treatment responses. In light of the additive suppression of HIV replication determined by pharmacological, immunological, and virological results, nelfinavir (NFV) as an addition to IDV/ZDV/3TC will be evaluated. Based on the potency of nonnucleoside reverse transcriptase inhibitors (NNRTIs) to suppress viral replication and the effectiveness of 3-drug regimens containing NNRTIs, efavirenz (EFV) will also be evaluated as an addition to IDV/ZDV/3TC.