In the auto industry when the manufacturer screws up, they have you bring the car back and they fix it, on their dime. This is called a recall. In the software world, you get what you get.
From SiliconValley.com:
Starting in June, Microsoft will charge users $49 for Windows OneCare Live, a subscription security service meant to protect you from the nasty malware that takes advantage of Microsoft's mistakes. You can't help but admire the vertical effectiveness of selling both the problem and the solution.