Fans of Linux (and I'm one of them) often claim that Linux is more secure than Windows. In many respects this is true but there are some important limitations to that claim. When people say this, it normally means that Linux is more secure by design. But that should never be taken to mean that Linux (or any operating system) is perfect.

When making a decision about an operating system (or indeed any software) it is also very important to consider how quickly vulnerabilities are fixed because they will happen.

So a blog post by Jeff Jones about 'Days of risk in 2006' makes interesting, if rather technical reading. Rather than measure the number of security vulnerabilities that surfaced in the year, he counted the number of days that these vulnerabilities were widely known but not fixed.

The winner but a significant degree was Microsoft with 29 days. Apple came in second with 46 days. Two of the larger Linux businesses did rather badly. Novell left users vulnerable for 73 days and Red hat a shocking 107 days. That's nearly a third of the year.

So, although Windows vulnerabilities make the news more often, regular updating keeps you safer.