HCV infection is common in patients infected with HIV. Patients infected with both HIV and HCV viruses seem to have more severe hepatitis C. A combination of IFN and ribavirin has been shown to lessen the severity of HCV. PEG-IFN is a modified form of IFN that stays in the blood longer, which means that patients would not have to take the treatment as often. This study will compare the safety and effectiveness of PEG-IFN to IFN when each is combined with ribavirin.