I'm not recommending unsafe computing practices.
I said buy good commercial antivirus and spyware applications and keep them up to date, and don't install every free scareware tool that some kid typed up in his basement. All the people who report the most problems have installed every doohicky and gadget they've found a free download for and wonder where all the crap is coming from.
But the list of antivirus and spyware apps, and other tools such as spam filters, software firewalls (esp good for controlling outbound malware), hardware firewalls (esp good for controlling inbound worms and hacks), and other such is getting longer. More tools are needed than just a year ago, as well as more expertize and more effort.