No agency is going to take on the liability of telling you that any test is 100% conclusive, because there is no test for any disease that meets that mark. Having said that, the 4th and 5th generation HIV tests are among the most accurate and reliable tests on the market, for any disease, and are considered by experts to be 99.8% by the 6 week mark. You're not going to find a test more accurate than that.
Normally, body goes through the process of sero-conversion at about 7-14 days post infection, that's why ARS occurs at that point, it is body's response to the alien interference, the human immunodeficiency virus in this case.
A week post sero-conversion, a large amount of infected population would start to yield positive result with an antibody test, i.e III generation test. Most HIV experts would factor a reasonable period to eliminate the possibility of delayed sero-conversion. Therefore, a three week buffer period is factored and a III Generation of HIV test is widely accepted as conclusive at 6 weeks.
A IV generation of HIV test is nothing but a combination of III generation antibody test with a P24 antigen detection. The beauty of this test is that it further shortens the window period from 42 days to 28 days.
Again, normally P24 antigen peaks at about 10-14 days during the process of sero-conversion, while ARS is taking place irrespective of being symptomatic or asymptomatic. If there is a possibility of delay in sero-conversion, the p24 ag would be detected at 21 to 28 days or as explained before, a large amount of infected people would test positive on the antibody test at 28 days. Hence, a IV Generation HIV test is suggested to be conclusive at 28 days.
A V generation of HIV test works on the principal of IV generation, the advancement is, this test can detect and identify HIV-1 and / or HIV-2 antibodies and the p24 antigen individually in one blood sample.
CurfewX has provided you an excellent advice, it's time for you to move on. HIV is not your concern.
Thank you, CurfewX and mike_no for your detailed responses. I will try to move on from this. Apologies for asking a question you have probably heard a lot!