OPSWAT's bar chart shows worldwide market share by percentage for security suites. Not surprisingly, free suites dominate. (Credit: OPSWAT)

While Avast dominates worldwide security suite usage, and Symantec leads in North America, Microsoft Security Essentials is rising fast, says a new study by OPSWAT, a software development tool and data service company in San Francisco.

OPSWAT's numbers confirm that free suites drive personal computer security, not surprising given the non-existent cost. From March 2011 to February 2012, Avast, AVG, Avira, and Microsoft combined for nearly half of the worldwide security suite market. While it's true that Avast, AVG, and Avira all have paid upgrades, and those companies won't reveal how many people use their free versus paid products, it's commonly believed that the vast majority of the people running them are running the free versions.

Avast clocks in with 16.26 percent, Avira at 11.65 percent, AVG at 10.96 percent, and Microsoft at 10.08 percent. The only paid suites that reach similar market share were ESET (10.06 percent) and Symantec (9.97 percent).

This pie chart shows the relative differences in North American security suite market share, according to OPSWAT. (Credit: OPSWAT)

North American market share reflects the same security suite makers, but with different rankings. Symantec comes in first in North America with 16.09 percent, followed closely by Microsoft at 14.92 percent. AVG has 13.22 percent, Avast notches 11.96 percent, with ESET far behind in the number five slot at 7.06 percent of the market.

Far and away, more people starting using Security Essentials in the past year than any other suite. Worldwide it jumped from 7.27 percent in 2010-2011 to 10.08 percent in 2011-2012, while in North America it rocketed from 9.94 percent to 14.92 percent.

The only software publisher in the top 5 to lose market share both globally and in North America was Avast, although OPSWAT doesn't clarify what suite they went to, if any, or even if the sample size has changed.