Hello Anand, if you are located in a country where One Care is supported :
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).
you can download One Care here - http://onecare.live.com/standard/en-us/default.htm?mkt=en-us&s_cid=WL2Hdr then use the product key contained in the retail package to activate. If you are in an unsupported country or using an unsupported language you might want to return the One Care software to the retailer it was purchased from.