The purpose of this trial is to compare the effectiveness, safety and tolerability of TMC278 given at a dose of 25 mg once daily versus efavirenz (EFV) at a dose of 600 mg once daily, when combined with a background regimen containing 2 nucleoside/nucleotide reverse transcriptase inhibitors ( investigator choice of ABC/3TC, TDF/FTC or AZT/3TC) in HIV-1 infected patients who have not yet taken any anti-HIV drugs. The following evaluations will be done: antiviral activity, immunologic changes, and viral geno-/phenotype evolution, relationship of Pharmacokinetics (PK) and PK/Pharmacodynamics and Medical resource utilization and treatment adherence.