When you install OneCare from CD, it always gives you 15 days until you are required to activate.
However, you have apparently already tried to activate. I suspect that the subscription has been created, but the credentials were not passed back to your PC.
Please sign in with your LiveID that you originally tried to activate with at http://billing.microsoft.com to confirm your OneCare subscription status. If it shows valid at the Billing site, the problem is indeed that the credentials were not passed back to the PC.
Open OneCare, and click Check for Updates. What happens?
Do you have any other security software installed? If so, please remove it. Try clicking Check for updates once more.
Try activating again with the same LiveID you verified as having a subscription active. If it wants payment or a key, it isn't the correct LiveID.
Consider reinstalling OneCare. When you reinstall, and then activate, once you sign in (with the confirmed LiveID for the subscription) it should recognize the subscription and bring the credentials back to the PC.
You've already contacted support via email. I don't think that they understood the problem based on the advice provided.
Respond back to support with the details - you activated a subscription, confirmed at the Billing site, yet OneCare is showing it is still in trial mode, now expired.
-steve
