How to access a webservice requiring certificate

I need to make a webservice call using C# to a webservice requiring SSl certificate.I have the cert file, and installed it.When,I browse to https url,it requests for a certificate(but no certs visible). How to do call webservice in code? Do I have to install the certifi开发者_JAVA百科cate?

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Try this (it is for the older framework but still works)

http://support.microsoft.com/kb/901183