To install the Cybertrust SureServer EV intermediary root certificate into IIS,
Please proceed as follows:
Download the following files:

Installation Instructions
Download and Install these certificates by double clicking on the corresponding file wizard

Install the GTE CyberTrust Global Root certificate(s) manually in the "Trusted Root Certification Authorities" store:

     "Show physical stores/Trusted Root Certification Authorities/Local Computer".

Install the Cybertrust Global Root and Cybertrust SureServer EV CA in the "Intermediate Certification Authorities" store:

     "Show physical stores/Intermediate Certification Authorities/Local Computer".