The primary objective of this trial is to compare the efficacy of boceprevir (SCH 503034) 800 mg three times a day (TID) orally (PO) in combination with peginterferon alfa-2b (PegIFN-2b) 1.5 µg/kg weekly (QW) subcutaneously (SC) plus weight-based dosing (WBD) of ribavirin (RBV) (600 mg/day to 1400 mg/day) PO to therapy with PegIFN-2b + RBV alone in adult participants coinfected with human immunodeficiency virus (HIV) and previously untreated chronic hepatitis C virus (HCV) genotype 1.