[Bud]

Wouldn't it be simpler and more efficacious to simply ban sales of Windows in the EU, or mandate that they fix the security issues?

Not that I favor ludicrous bans of this sort, or that I think they will work. Because I manifestly don't. But geez, if you're going to be over-the-top Orwellian, at least do something that has a chance of achieving your stated goals.

[jjcm]

It seems naive that you assume that banning Windows would decrease the rate of successful malicious attacks on machines. Every piece of software has holes - the largest of which is the user. If everyone in the EU switched off of Windows, you'd just have a large percentage of the population using linux or OSX without understanding how security works on those systems (many of whom would gladly enter their root password to install a spyware program, so long as they can keep playing farmville or whatever it promises to do).