To compare the long-term virologic response to combination therapy with two protease inhibitors, i.e., nelfinavir (NFV) + saquinavir soft gel capsule (SQVsgc) and delavirdine (DLV) or combination lamivudine/zidovudine (3TC/ZDV, Combivir) versus NFV and 3TC/ZDV, in the proportion of patients demonstrating virologic success (< 500 copies/ml HIV RNA) at week 48, without prior virologic or clinical failure. To evaluate the safety and tolerance of combination protease inhibitors.