To compare the two treatment groups with the goal of achieving HIV-1 RNA levels less than 50 copies/mL at week 48.~To compare the safety, efficacy and tolerability of the two treatment regimens through 144 weeks of drug exposure.~To evaluate the long-term efficacy, safety and tolerability of tenofovir DF in combination with lamivudine and efavirenz through approximately 336 weeks of drug exposure.
To compare tenofovir DF plus lamivudine plus efavirenz vs. stavudine plus lamivudine plus efavirenz in the treatment of HIV-1-infected patients who have never taken antiretroviral drugs and have a viral load of less than 400 copies/mL at week 48.