Issue: You need to process a pending SSL certificate request by installing the completed cert downloaded from your certificate authority.
Solution: Follow the below instructions for Windows 2003 IIS 6 to install your certificate and complete your pending certificate request.
Note: These steps assume you have already successfully generated a CSR and submitted it to your chosen third party certificate authority.
Steps: Go back into IIS Manager, expand Web Sites, right click Default Website, click properties.
Click Directory Security > Server Certificates
The Web Server Certificate Wizard will open, click next.
Click Process Certificate Request:
Click Browse and select the certificate file you received from the third party certificate authority (GoDaddy etc)
Click Ok and Next / Finish to process the pending certificate request.
If you haven’t already done so, you will need to import the intermediate certificate from your certificate authority.
Your IIS 6.0 default website can now utilize port 443 SSL encryption for Outlook Web Access and Exchange ActiveSync sessions. If you purchased a wildcard or multi-domain certificate and want to use your new certificate on other servers you will need to export your certificate from IIS to a .pfx file and import the .pfx into the other server.