I have created Site Collection under Web Application, but not able to connect to Site Collection. Its popup window to enter "Windows Credentials".

Which credentials i have to enter? What is the reason for this error?

when creating the site make sure that you have admin rights on the site.

if you are using the SharePoint machine itself to browse the site, you must disable loopback check

http://sp-vinod.blogspot.com/2013/03/disable-loop-back-check-in-sharepoint.html

Hi frnd i am having admin rights on the site. even though i am not able to connect to site collection. What is the reason?