Symantec's 11th Internet Security Threat Report says that Microsoft's Windows is currently the most secure operating system. Which rather gives the lie to Apple's smug advertising campaign (although I strongly suspect that Apple advertises only to get up the noses of Microsoft mandarins).

Symantec finds that Windows had the fewest relative number of patches and the shortest patch-development time of the five major operating systems it monitored in the last six months of 2006.

More than 35 Windows vulnerabilities were found, each taking an average of 21 days to fix. That may seem like a long time, but consider the opposition.

Next safest, according to Symantec, was Red Hat Linux. This took an average of 58 days to address a total of 208 vulnerabilities. (It sounds shocking, but vulnerabilities in Red Hat weren't as severe.)

Which brings us to Mac OSX - the self-styled 'safe OS'. According to Symantec, the Apple software's performance was well below that of Windows. OS X - the cool, chilled out entertainer of operating systems - had 43 vulnerabilities and a whopping 66-day turnaround on fixes. All that sitting around in Hoxton wearing combat trousers does get in the way of securing your Mac, it would seem.

The 66-day patch turnaround is a nice headline figure, of course, but it doesn't really tell the whole story. Only one vulnerability was high priority. And while Apple took on average 37 days to fix flaws, I have a Mac at home, connected unprotected to the web, and I'm less than concerned about its health. My Windows XP PC, on the other hand, is rarely connected to the net.

Do you feel more secure on Windows than on any other OS? I'm not sure I do. The very nature of malicious code-writing means that the biggest target is always going to be the biggest product. Microsoft is clearly pretty slick at fixing holes, and its software is well written anyway, but as long as there are criminals there will be attacks on Windows. As long as Windows is number one, Mac users will be able to sneak under the radar - to a certain extent.

Still, it's quite nice to wipe the smirk off certain Mac users' faces. And dealing with security threats will give them something to do when they're, er, not playing the games they can't play on their beloved computers.

For the record, HP-UX from Hewlett Packard and Solaris from Sun prop up the security league table. HP-UX had 98 vulnerabilities in last six months of 2006 and took 101 days to fix them. Sun, took 122 days to fix each of 63 vulnerabilities.