 This observational study is supposed to assess under conditions of clinical practice in daily routine whether treatment with Viramune nevirapine in combination with ARV, e.g. Combivir Zidovudine and Lamivudine, Kivexa Abacavir and Lamivudine or Truvada tenofovir and emtricitabine will durably suppress viral load below the limit of detection or will maintain suppression of viral replication HIV-RNA below limit of detection achieved under previous anti-retroviral combination therapy after switch to combination treatment of Viramune nevirapine and ARV, e.g. Combivir Zidovudine and Lamivudine, Kivexa Abacavir and Lamivudine or Truvada tenofovir and emtricitabine. 