Issue: When clicking on "Subscribe Now" or "Add Another PC" or trying to activate OneCare you are redirected to http://get.live.com.
Resolution: Go into Internet Explorer and click Tools / Internet Options and click the Languages button. Change the language to reflect your current geographic location and click OK.
This can also happen if you are trying activate a subscription and your geographic location is not one of the countries where Windows Live OneCare is available for purchase.
See the FAQ located here for a list of countries where OneCare is currently available - http://onecare.live.com/standard/en-us/faq.htm (this is the US site, you can navigate to the FAQ for your locale by starting at http://onecare.live.com)