Patients receive a treatment regimen of adefovir dipivoxil, abacavir, efavirenz, and amprenavir for 24 weeks. During the study, patients are evaluated for changes from baseline in plasma HIV-1 RNA levels and lymphocyte subsets and for development of adverse events and toxicities. Patients who experience virologic failure are discontinued from the study. After Week 24, patients with documented virologic response are eligible to continue receiving the study treatment and to attend scheduled follow-up visits.