The thing that makes me continue to laugh about /. style linux-weenie MS-bashing is that people continue to pay for the stuff. Some call it ubiquity, some call it anti-trust. But you've got to hand it to MS though. They've made a fortune, and many people fortunes.
It has its place and, correctly set up, it can just keep on working.
The most likely thing to bring a Windows machine to its knees is its user.