 Antiretroviral ARV treatment regimens consisting of EFV and two NRTIs are the most commonly prescribed regimens for the initial therapy of HIV-infected people in the United States. Such regimens are popular because the drugs are easy to administer, have overall excellent efficacy, and are well tolerated. However, because of concerns about long-term drug toxicity, the development of drug resistance, and potential complications in pregnant women, it is imperative that other drug combinations be investigated as possible alternative initial regimens. Drugs recently approved by the Food and Drug Administration FDA for HIV treatment include the protease inhibitor PI atazanavir ATV and the two NRTI coformulations emtricitabinetenofovir disoproxil fumarate FTCTDF and abacavirlamivudine ABC3TC. Data are limited on the efficacy of these new drugs when part of anti-HIV drug regimens. This study will evaluate and compare the safety, tolerability, and efficacy of four different treatment regimens in HIV-infected treatment-naive adults. 