title: why do we need the pfx (key exchange) file?
body: <p>If we make the private key exportable (using -pe option in makecert), then in theory we have both an exportable private key and the public key (public key in certificate) -- which can be transferred or imported to another machine.</p>
  
  <p>So, my question is, why do we still need to create the .pfx file (key exchange file, which contains private and public keys) -- making the private key exportable in certificate could do anything we want? Any scenarios pfx file could cover which making private key exportable in certificate could not achieve?</p>
  
  <p>thanks in advance,
  George</p>