This 3 arm study will assess the safety and efficacy of combination treatment with PEGASYS + Copegus in patients with chronic hepatitis C. Three groups of patients will be studied; 1) those with elevated ALT level, 2) those with normal ALT level, and 3) those with HIV co-infection. Patients with genotype 1, 4, 5 or 6 will receive PEGASYS 180 micrograms sc once weekly + Copegus 1000-1200mg po daily (dependent on body weight) for 48 weeks, those with genotype 2 or 3 will receive PEGASYS 180 micrograms sc once weekly + Copegus 800mg po daily for 24 weeks, and all patients with HIV co-infection will receive PEGASYS 180 micrograms sc once weekly + Copegus 800mg po daily for 48 weeks. The anticipated time on study treatment is 3-12 months, and the target sample size is 100-500 individuals.