Dear tetontob,
thank you very much for your help.
It tooked me much time in understanding all the procedures in your last post... although the work to do was poor!
Thanks to your suggestions, I will read all the proposed articles and will surf much more safely in the future!!
Going back to the beginning, I think I get stupidly infected opening a P2P file before scanning it with AVAST
If you come to Italy mail me a message !!