Many patients experience virologic relapse (increase in viral load after sustained viral load suppression) within 1 to 2 years of taking anti-HIV drugs. The approach to treatment for patients who experience virologic relapse while on a highly active antiretroviral therapy (HAART) has not been defined. Current guidelines recommend switching to a new treatment regimen as soon as possible to prevent HIV from becoming even more resistant to anti-HIV drugs. However, there is evidence that patients can benefit from staying on the same HAART drugs, even after virologic relapse. This study wants to find what happens when drugs are changed immediately after virologic relapse (when the viral load is lower) compared to what happens if drugs are changed only after a delay (when the viral load is higher).