Computer viruses are still rampant. In Consumer Reports' latest survey, one in seven Americans had serious problems with viruses, costing almost $3 billion in estimated damages. Consumer Reports just tested security software to see which offers the best protection.

Consumer Reports tested 10 Internet security software programs you have to pay for - like McAfee and Norton from Symantec - as well as software you can download free.

"We had an outside lab create some variations of known viruses, which we keep on a disc in a safe here in the lab," said Dean Gallea of Consumer Reports. "We ran them on a virtual machine, which is a virtual computer which is completely physically and electrically separated from any other computer or network."

Those viruses were used to test the software to see if it would detect them.

"To test the anti-spam programs, we ran a 'bad e-mail' test to see how well the programs could detect real spam that we collected and a 'good e-mail' test to see how often the software actually removes e-mail you wanted to keep," Gallea said.

McAfee and BitDefender both came out on top in Consumer Reports' tests. They sell for $50 for a year of protection.

"If you just need basic protection and you can be sure that everybody practices careful computing at home, then freeware can be a good option," said Gallea.

Consumer Reports tested three free programs that you can download: Avira's antivirus software, Microsoft Windows Defender
anti-badware program, and SPAMfighter's anti-spam software. All are easy to use.

One way to protect your computer is to turn it off when you aren't using it for long periods, or at least disconnect it from the Internet. That reduces the chance that a malicious computer can access your operating system. You can get more advice on how to practice safe computing on the Consumer Reports Web site here.

(Note: This report is based on an article in the current September 2008 issue of Consumer Reports magazine, pages 33-36.)