mi2g has concluded that Windows OS contains more security vulnerabilities than either Linux or Mac OS X.
The report, which lives here, accounts for market share percentages.
mi2g's report also reiterates two, principal advantages of open source.
First, Windows consumers have to wait for Microsoft to release patches that address security flaws. With Linux, on the other hand, developers can take matters into their own hands, and tweak faulty code as the need arises.
Second, although "Linux source code can be easily probed and examined by hackers it is also open to the scrutiny of the rest of the world and is therefore more robust and reliable as a result".
Microsoft is not thrilled with these findings, Yahoo reports.