Patients receiving combination antiretroviral therapy with indinavir (IDV), zidovudine (ZDV)(or d4T) and lamivudine (3TC) show viral suppression for two years or more. Discontinuation of one or two of these drugs results in prompt loss of the viral suppression. Other studies show that addition of HU to some reverse transcriptase inhibitor treatments results in increased antiviral effects. This study will provide further information on the effect of adding HU to a treatment regimen with respect to long-term viral suppression.