By switching to a non-Microsoft browser, Windows XP users can halve the number of vulnerabilities that apply to the OS, according to a survey of flaws Microsoft fixed in the second half of 2013. The statistics support the advice from security professionals, who have recommended users run a rival browser to avoid some of the attacks aimed at their unprotected PCs. Microsoft stopped sending patches to Windows XP PCs last month. The ban also applies to any version of IE that runs on the aged operating system. But a tally of Windows and IE vulnerabilities patched from July to December 2013 shows that the browser poses a greater security risk to XP bitter-enders than does the OS itself. During the six-month stretch, Microsoft patched 19 separate critical vulnerabilities in the versions of IE -- IE6, IE7 and IE8 -- that run on Windows XP.