The HALT-C Trial is a National Institute of Diabetes and Digestive and Kidney Diseases sponsored, randomized clinical trial of long-term use of Peginterferon alfa-2a (pegylated interferon) in patients who failed to respond to prior interferon treatment. All patients who enter the trial will be treated for 6 months with Peginterferon alfa-2a and Ribavirin. Patients who respond to this 6 month treatment will continue to be treated for an additional 6 months.