OK..I got this working with the following steps
in Web.config, replaced all 1.1 with 3.5.0.0 version extensions
deleted system.web.extensions from bin
1)Create a certificate service request in IIS
2) Sent the request to RapidSSL
3) Got the new certificate
4) Went to IIS Admin --->Website-->Properties--->DirectorySecurity-
Clicked certificates and completed the existing request. I can view the cerificate and it shows properly
5) In Site settings, enable SSL, enabled SSL Enforcing
6) In Login and UserAccount pages, checked the "Secure" checkbox.
Make sure port "443" is open in your firewal..In my case, the port was closed by default and when I opened the port, it all started working.
Thanks..to all who responded
Now I have a different issue..everytime Login page is displayed, I get this error page, "This page contains both secure and non-secure".
I think I will have to see if there are any http references