Actual solution for this issue is to add Multi-String registry key named BackConnectionHostNames in SharePoint installation server registry to
path and for it’s value give each of your domains(the the domain names you types in web browser) seperated with a new line.
If you have setup sharepoint server 2010 in windows server 2008 R2 you might have a issue of login into sharepoint site which has been setup in port 80 with host headers. When you try to access your site you might get prompted with windows login box but when you enter correct credentials you might not be able to log into site until 3 times you enter credentials it keeps popping up the windows login prompt dialog and after that nothing happens. So what is the solution to this issue. Fortunately I found this blog post by Dinesh. After doing that I had my Sharepoint site working.