Kindly go through the below link:
Please review the sap note-1584110.
Hope this inofmration helps.
Please check the below link-
Thanks for your reply.
I followed one document from this forum which talks about the LDAP configuration. Now I have configured MS AD with the help of LDAP. Users are not asked to authenticated first before accessing services:Password self-service and Register Security Questions
This worked for me as of now
Let me see how I can make use of ADS.
Thanks for your help!!!