Assuming this is true, this would not be a valid reason to consider Windows a less secure OS than OSX. Security depends on much more than that.

But, in any case, is it true?

1. When has Winodws NT3.5, 4.0, 2000, XP, Vista, 7, been single user? Windows 3.x, 95, Millennium are a >different< OS, starting from Kernel up.

2. Would you please provide or point me to any official paper, tech specification, factual technical evidence that supports your statement? And, please undertsand I am not referring to historical data. I am referring to Windows 7 vs OSX in their respective latest versions.

Please, understand I don't mean to disagree with you or challenge your statement for the sake of it, or prove you wrong. I don't have an opinion myself on that (Windows 7 and OSX inherent technical security) nor >>real<< data, in spite of the hundreds of articles and opinions one reads here and there in years, to support any specific view. I just want to separate generic personal appreication for this or that product from from facts, and since you are a very strong supporter of one of the two platforms, I am honestly curious to understand exactly what you are referring to.

See, in the last 10 years I've seen, on the field, hundreds of Windows machines in public locations in our organization used by hundred of users per day, and I have real stats on that. Never a machine was infected by malware or viruses beyond the boudaries of the user environment, never the OS was compromised, and we don't reinstall the OS for years (3 to 5, which is simply the life-cycle of the hardware), and never because it "naturally slows down" as the common popular belief would suggest: never we've seen performances decrease because of simple, standard daily usage by a very wide range of different users, ranging from complete user illiterates to fairly advanced ones, all with everage/high level of education.
I mean: never.
So, see, while my experience would 100% support the idea that Windows by default puts uses in the condition to do a lot of damage still today, that does not at all reflect what the OS is technically capable of and how safe it inherently, thechnically, is.
And actusally, all this is based on the 11-year-old Windows XP.

In any case, any additional info is useful and welcome.