Thank you for taking time to answer my question. After reading, I still could
not make the thing work. Here is what I did.

(1) Winhttpcertcfg.exe -i PFXFile -c LOCAL_MACHINE\My -a “AccountName”. It
is successful.

Then, I looked for current dir where PFXFile residents, there is no new
files. But I need a *.cert file to construct a X509Certificate, right? Where
could I find it? Ok, in the doc pointed by URL “If you are using the .NET
Framework 1.1, you must first export the key to a DER-encoded file. You must
export the key because the
System.Security.Cryptography.X509Certificates.X509Certificate class does not
contain methods to directly access the details of a certificate from a
certificate store. Therefore, the application must read the details of a
certificate from a DER-encoded file.”

How could I export the key and what is the key? I tried to cut cert key
portion of PFXFile and use X509Certificate.FromBase64String to get
X509Certificate, but it failed with "Could not establish secure channel for
SSL/TLS".

Any clue will be appreciated.

Thanks.

Thanks a lot!