Your one-stop shop for free online PC scans

Too often we choose a security program based on the reputation of the vendor. That's why I was happy to learn that the results of recent tests of antivirus software conducted by AV-Test.org found several with near-perfect virus-detection rates, including Avira's free AntiVir Personal.

The tests didn't distinguish between antivirus programs that reside on your PC and virus scanners that run in a browser. I wasn't able to find any test results specifically for online virus-scanning services, though the same handful of names popped up repeatedly: Secunia Software Inspector, Trend Micro HouseCall, Kapersky Online Scanner, F-Secure Online, Microsoft's Windows Live OneCare Safety Scanner, and the Jotti Malware Scanner.

Over the years I have used all of the above services at least once, with the exception of Jotti. While I've never experienced a problem using any of them, neither can I be certain that the services didn't miss a virus that had infected the PC being scanned. Even running multiple virus scanners in succession is no guarantee that one of them will find the bugs the others missed.

PC Flank offers more scanning options
Absent any third-party test results, how do you choose from among the many virus-scanning services available? If you're looking for a service that lets you choose which type of scan to perform, PC Flank offers a battery of tests that you can run individually or together.

If you're looking for a quick check of your PC's defenses, choose PC Flank's Quick Test, which determines your PC's vulnerability to Internet attacks, whether your system is infected with a Trojan horse, and whether your browser is disclosing private information to the sites you visit.

Get an instant check of your PC's vulnerability to Internet threats using PC Flank's Quick Test.

(Credit: PC Flank)

When the test results appear, click the Full Report button to see more information about your system's defenses. The service may recommend that you update your antivirus program's definitions, or install a new firewall (which is what I was instructed to do for my laptop).

PC Flank's security scanner may recommend that you update your antivirus program, or install a new firewall.

(Credit: PC Flank)

For more in-depth probes of your machine, try PC Flank's Stealth Test, which lets you know if the system is visible on the Internet, or the Exploits Test, which mimics a denial-of-service attack on your PC. The service even recommends the best test to run based on your experience level, or whether you're in a hurry. It also provides a list of leaktests and a summary of how well various firewalls did when tested for leaks.

Tomorrow: A different kind of online scanner keeps your PC "pure."