Thank you all for your answere´s.
But... i read here in this forum, that people´s got an infect on there pc.
How the infect there system while using avast? What made they wrong?
Well, if you visit other AV's support forums,
(the ones that do not delete anything that could be viewed as negative for them, thats a small thank you to Avast! for not over using their powers of censorship),
and you will find this failing often. It is the same failing doctors have fighting disease. They are stuck in an (almost) totally reactive system.
The other half of the problem is the end user his/herself. But that problem has been around since long before computers.