In this open-label, nonrandomized study, 120 HIV-infected patients are stratified into two groups: failed nelfinavir vs protease inhibitor-naive. All patients receive indinavir plus efavirenz plus adefovir dipivoxil plus and L-carnitine, orally. Plasma vRNA is measured every 4 weeks until Week 16, then every 8 weeks for the remainder of the 48-week study.