Well, I've tried to restore a file and the Avast UI stopped responding. I've installed a program that I trust, since it's on some download sites (softonic, tucows and so) and I did not see it has malware. to download and convert youtube videos. Avast detected an PUP a dll of that program, who manages the video downloads. I reported it as a false positive, added to exclusions list and I go to restore it. Windows 7 UAC ask me to give rights to VisthAux,exe to copy it since Program Files is protected. I press yes and the UI just stop working. If you need anything just ask. Thanks for all!
P.D. I use Avast 5 Free over Windows 7 Ultimate 32 bits. All updated to latest versions.