At entry, patients undergo HIV genotypic/phenotypic analysis. Patients continue their current antiretroviral regimen but are randomized to receive one of four doses of PEG-IFN or PEG-IFN placebo administered subcutaneously once per week until results of HIV genotyping/phenotyping are available (approximately 4 weeks). Patients who respond with a 0.5 log or greater decrease in HIV RNA at Week 4 have optimized HAART added to their ongoing PEG-IFN regimen and are followed for 24 weeks in an observational study.