Quick Links

Go to Key Manager.
Install the new IIS SSL Server certificate by clicking on the key in the www directory (usually a broken key icon with a line through it), and select "Install Key Certificate".
Enter the Password.
When
you are prompted for bindings, add the IP and Port Number. "Any
assigned" is acceptable if you do not have any other IIS SSL
certificates installed on the web server.
Note: Multiple
certificates installed on the same web server will require a separate
IP Address for each because SSL does not support host headers.
Go to the Computers menu and select the option "Commit Changes", or close Key Manager and select "Yes" when prompted to commit changes.
The new IIS SSL Server certificate is now successfully installed.
Back up the Key in Key Manager by clicking on Key menu> Export -> Backup File. Store the backup file on the hard drive AND off the server.
Step 2: Installing the Root & Intermediate Certificates:
Your IIS SSL Certificate will have been emailed to you. The email will also contain three other Certificates: AddTrustExternalCARoot.crt , UTNAddTrustServerCA.crt and OptimumSSLCA.crt - save these Certificates to the desktop of the web server machine.
It is essential that you have installed the UTNAddTrustServerCA.crt and OptimumSSLCA.crt certificates on the machine running IIS 4.
Once you have installed the
Certificates, restart the machine running IIS 4. You must now
complete one of the following procedures - the procedure you follow
is dependent on the Service Pack that has been implemented on your
machine running IIS4.
Service Pack
3:
Install the above certificates in your Internet Explorer by opening each certificate and clicking "Install Certificate". See Microsoft KnowledgeBase Q216339).
Service Pack
4:
Install the above certificates manually in a specific root store (you may also want to read (see Microsoft KnowledgeBase Q194788):
Service Pack
5:
Same as
SP4.
Service Pack
6:
Same as
SP5.
Reboot the web server to complete the installation.
IIf you have any problems with the installation of your certificate on IIS 4x, check you have installed the root and intermediate certificates correctly, by following the instructions here