Installing your Certificate with Website Pro 3.x
When your certificate is issued you will receive 3 certificates:
Yourdomain.crt
ComodoClass3SecurityServicesCA.crt
GTECyberTrustGlobalRootCA.crt
- Add the ComodoClass3SecurityServicesCA.crt certificate as Trusted Roots:

- Then attach each certificate in turn to your websites Key Pair in the following order. At this point your Key Pair will be black.:
Yourdomain.crt
Intermediate CA certificate
Root certificate

- Your Key Pair will now turn green.
- Stop and Start the server, your site can now be found using the https entry