The best way to install OneCare on *any* PC is to go to
http://onecare.live.com and install the trial. Once installed, open OneCare and click on the link to Subscribe. Sign in with the subscription LiveID for your subscription and it will be activated and become part of your Circle/subscription.
-steve
Microsoft MVP Windows Live / Windows Live OneCare, Live Mesh, & MS Security Essentials Forums Moderator