Advise best freeware against malware.
I have Win Xp 2003 with its usual security, Avast and Spybot.
Originally used IE but changed to Mozilla when I had problems.
In December used a free scan offered by tech site and it found a number of spyware entries on C drive but my latest Spybot / Avast don't.
I downloaded Spycatcher Express which caused problems opening personal settings.
Please advise best freeware to prevent and remove malware.