Free is not always better. Those free antivirus protection programs that you can get are not as extensive as the versions you have to pay for. As the article explained, the ILOVEYOU virus/worm was transmitted via email and most of the free antivirus security systems do not protect your email.
Consider buying a full-range antivirus protection program if you want to be better protected. Even with one of these, there are no guarantees, but your odds of avoiding a system infection definitely increase with a better security package.