Unfortunately, your choices are uninstall OneCare when it expires or travel to a country where OneCare is sold and can be activated. You won't be able to purchase online since your Billing address would not be in the country you are activating from.
In which countries and languages is Windows Live OneCare available?
The Windows Live OneCare subscription service is available in the following countries and languages: Australia (English), Austria (German), Belgium (Dutch, French), Canada (English, French), France (French), Germany (German), Ireland (English), Italy (Italian), Japan (Japanese), Mexico (Spanish), Netherlands (Dutch), New Zealand (English), Singapore (English), Spain (Spanish), Switzerland (French, German), United Kingdom (English), United States (English, Spanish).
Pasted from <http://onecare.live.com/standard/en-us/faq.htm>
-steve