Read how we rate antivirus software. Click on the links below to download your choice of packages, and click on the screens, including the chart thumbnail at right, to enlarge them. (The chart shows how well the seven packages reviewed performed in our tests.)
The reviews here appear in order of scoring.
AVG Anti-Virus Free Edition
Our top pick, AVG Anti-Virus Free Edition 2012, performed well in virtually all of the tests we ran.
In our real-world malware detection tests, which evaluate how well an antivirus package will block brand-new threats, AVG's freebie blocked 85.7% of the samples, tying for the best result among the programs we tested. It detected 98.7% of the more than 129,000 samples of malware from the past four months in our malware "zoo" test. That's a good score, although a bit short of the best results we've seen.
AVG was at the top of its class in disabling active malware infections: On our test PC, it detected and disabled all malicious software, and removed all traces of malware two-thirds of the time.
AVG also scans a PC relatively quickly. When we directed it to check 4.5GB of data, it sped through the job in 1 minute, 35 seconds, the third-fastest time in this test and only 4 seconds slower than the fastest. Its on-access scanner—which runs when you open or save a file—took 4 minutes, 55 seconds to go through the same amount of data, about average for the programs we looked at.
I like AVG's main interface, though its advanced settings could intimidate some users. Apart from that caveat, if you're looking for solid, fast PC protection, look no further than AVG.
Avast Free Antivirus
Avast's freebie finished second in this year's roundup. Avast Free Antivirus 7 mostly excelled in protecting against malware, it has a versatile interface, and it sped through our battery of malware tests.
Avast's defenses were weakest at blocking new real-world threats: It caught just 78.6% of them—not outstanding, but slightly above average. Avast did far better at stopping well-known malware, detecting 99.1% of samples in our zoo test—a very good showing. This package cleans up malware infections effectively, as well. It detected all the malware residing on our test PC, and disarmed the invaders 93% of the time, tying for second-best in this test. The utility also removed all traces of infections two-thirds of the time.