For Malware type security I use a cocktail of apps (using the old "eggs & basket" analegy) Spybot S&D, CCleaner, Malwarebytes, along with using Firefox with Adblock plus addon installed, also remembering for the more iffy sites theres also inprivate browsing option on IE8 and Firefox which doesnt store any site info or cookies etc.
It' worth mentioning I dont use memory residient malware scanning, merely run on demand modes...to avoid conflicts with my Antivirus app.