No troubles with Windows XP Home. Take it easy… 8)

avast! is the best antivirus running today. The virus definitions - as whocares smartly answered - join lots of “family” virus. For the question about the Professional version, the answer is no: the user has the same definitions for free (Home) and Professional version. The differences are in the customization features and high Internet protection (see http://www.avast.com/i_idt_1018.html) :wink:

By the way, I´m an avast! user not from avast! corporation (Alwil Software) :wink: