Since you have a subscription, you now need to activate that installed copy with the LiveID for your original subscription.
If you don't recall the LiveID you used for your subscription, you will need to contact support who can provide that information to you using your Key and/or contact information.
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
Alternatively, sign in at http://billing.microsoft.com with email addresses that you have set up as LiveIDs and one will show your subscription listed - that would the LiveID to use to activate with.
If the activation dialog already contains a LiveID from a prior attempt or one used in trial mode, but this is not the one you need to activate with to associate it with your subscription, see this post for how to reset this - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2776450&SiteID=2
For more information see Instant Help - http://help.live.com/help.aspx?project=onecarev2&mkt=en-us&querytype=topic&query=OneCare_PROC_FindLiveIDHelp.htm
If you prefer to cancel the subscription, then contacting support is the way to go, but you say you've already done this with no reply by using the email form. If you can provide any case IDs, I can have someone check what happened.
In the meantime:
Unofficial path - send me an email at sboots@mvps.org with a subject line including "OneCare" (to get past my spam filtering) and in the message body, tell me what country you are in, your forum nickname, and paste this link:
http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=4075336&SiteID=2
I am not online 24x7, so you may be waiting for a reply, but I'll do my best to hook you up with support.
I'm moving this thread to the Install/Activate topic folder.
-steve
