I have a Dell Inspiron notebook with windows media centre sp2 . I installed Zone alarm pro,Ad-aware,Spybot S&D and Avast anti vir Pro before getting an always on broadband connection(so called). I used Bit comet the most for dwnldng. After three days my sys began hanging very often so i ran a full sys scan by Avast and others and to my horror 8 virus and various other spyware were found. i deleted most of them and repaired others but my sys continued to hang repetedely and so finally i restored it to an earlier state by an image by Norton ghost which came pre installed with my system and then it began working fine. Can anyone plz help me to secure my system and explain me what my software were doing while my system was being infected