I was concerned with the bad functioning of Hijackthis, which in my case does not "Run as administrator" and instead of the log it gives me back a blank window, so I found this post http://www.computing.net/answers/se...
I understand now that, in that post, the user was preoccupied by giving his personal data in public, which I wasn't, but I really didn't notice it at that moment, because I just wanted to find an alternative to Hijackthis which was not working properly.
I just happened to receive help from maksimog, which continued "in private mode" without asking me "why you didn't do this, why you didn't do that", he just helped.
I apologize for not following the rules, I just received help. But now I have learnt the lesson.
Thanks to all for your understanding.