the answer to your question is probably.
there is no such thing as 100% ... and there are many different types of threats ... from phishing and spoof (which both rely on your gullibility - through adware to keyloggers and rootkits. No single product will get all of them
(currently AVG is regarded as having an 84% detection rate, AVIRA 92% and Kaspersky 98% {no one got 100!})
Avg (virus) doesn't destroy spyware
ad-ware does (but not viruses)
neither can even see a rootkit
so you need to assemble a toolkit that will keep you safe.
Don't believe everything you read either .... google can be a godsend ... but just because fred bloggs of Baltimore was "delighted" by the performance of the black death scanner and thinks it's worth every penny - doesn't mean a thing. If you are serious ... stick with mainstream software or progs which are recommended by a source you know to be legitimate
with all respect to ethel .... you should never use a download service (or tinyurl) to obtain software if the software vendor has their own site .... phishing and viruses can be spread from third party vendors (and because tinyurl obscures the address ... you have no idea where you are likely to end up).