Norton AntiVirus 2010 will be the fastest and lightest malware scanner Symantec has ever delivered. The Norton AntiVirus application scans faster and uses less memory than any other antivirus product on the market. Unlike free solutions from Microsoft, Norton AntiVirus includes intrusion detection to detect malicious code hidden in web sites before it can strike.

And Norton AntiVirus’s pulse updates ensure that you are always plugged into Symantec’s global security grid and you are never more than a few minutes away from the latest update. Improved Norton Safe Web technology blocks Internet threats before they can infect your PC. So you can browse, buy and bank online with confidence. Plus, unlike other antivirus products, Norton AntiVirus 2010 provides easy-to-understand threat and performance information to help you avoid future threats and keep your PC running

The company Panda Security has released a Panda Cloud Antivirus - the world's first free "cloud" the antivirus, which is entirely based on the principle of protection "from the clouds" in real time.
Ultralight "thin client" to help protect your computer affects the performance of a PC on average 50% lower than traditional anti-virus. With Panda Cloud Antivirus company Panda Security presents a new security model, which uses agent "thin client" installed locally on your computer and communicates with servers Panda.

Avira Antivir has received an increasing amount of attention since garnering the highest score of any free security program on AV-Comparatives independent testing service for on-demand testing.

It fares a bit worse on the "Retrospective/ProActive" test, although still better than any of the other applications tested. However, it's hard to find anybody who finds the virus definition file update speed to be fast: it's notoriously slow. We put Antivir through the CNET Reviews Labs benchmarking process and came up with some unsurprising results.

When running alongside other high-drain processes, such as iTunes file conversion and while running MS Office, Antivir scored high. CA Antivirus and Panda 2008 were the top two products, followed by the premium version of Antivir and then the standard version, but all others tested including AVG Anti-Virus, Kaspersky, and Avast fell in behind them.

The MS Office test produced far less staggering results. With Antivir Personal completing the test in 271 seconds and Antivir Premium finishing in 270. The fastest of the 12 products, Panda 2008, scored 269.67 seconds, while the slowest, F-Sure, hit 273.33, so Avira was more toward the average here than in the other tests.

Overall, Avira slowed down the test machines somewhat, but it caused less drag on system resources than most--but not all--of its competitors. Boot time tests placed it at an average of 30.85 seconds, one second slower than Kaspersky, two seconds slower than BitDefender, and nearly two and a half seconds slower than the premium edition of Antivir. In scan testing, Antivir scored second-fastest after Panda 2008, and nearly three times faster than AVG Anti-Virus 8.0.

Combined with its high marks for removing and preventing infections, I remain convinced that Antivir is the best free antivirus on the market right now.