My email client will download the email with the attachment. Nothing happens.
I click on the attachment. My email client will ask me what I want to open the attachment with, the default being a hex editor. Again, nothing happens.
I open up a console window and change to the attachment directory. I type the name of the attachment. The operating system responds "Permission denied".
In order to execute the attachment, I must deliberatly issue "chmod +x attachment" before it will execute. And even then, the worst it can do is damage, delete or change files in my home directory. No other user's files and no system files can be damaged.
These are fundamental differences between how unix-type operating systems and Windows-type operating systems are designed. The amount of damage that a Code Red or a Nimda outbreak can cause shows this.
And the blah, blah, installed users, blah, blah, popular platform, blah, blah standard excuse doesn't cut it. Apache still holds the largest market share of web servers, yet IIS has had many more damaging attacks.
Like MSDOS, Amiga, MVS and C/PM, Windows-based operating systems are out of date. Those people that continue to use outdated, buggy, and unsecure legacy software will continue to have problems.