Setup SSL for Web Site

I have installed Certificate Authority on our Server and configured the root CA – all seems to be functioning properly. I requested, issued, and installed a certificate on my website, edited the directory security tab to require SSL. checked to makesure the certifiacte is installed. checked to make sure that 443 is configured under web site tab properly. I get a SSL – forbidden error when I try to access the site using http://
but when I try https:// I get page cannot be displayed. Does anyone know what I’ve missed?? All the documentation I’ve read says it should be working at this point! HELP?