Respond to Requests Requiring a Client Certificate
To specify the .CER file for Fiddler Classic to return for a given session, add this FiddlerScript*:
oSession["https-Client-Certificate"] = "C:\\test\\someCert.cer";
To specify a .CER file for Fiddler Classic to return otherwise, place that .CER file in:
%USERPROFILE%\My Documents\Fiddler2\ClientCertificate.cer
To generate a .CER file:
Install the certificate in the Current User's Personal Certificate Store.
Right-click the certificate in Personal Certificates Store.
Click All Tasks > Export....