SSRS Keeps prompting for username and password when trying to access the website

https://social.msdn.microsoft.com/Forums/sqlserver/en-US/9ef2f893-648b-46d3-9339-9fd06075570a/ssrs-prompting-for-usernamepassword-when-trying-to-access-the-report-installed-on-a-server-from?forum=sqlreportingservices

1. Open the rsreportserver.config(By default, it can be found from C:\Program Files\Microsoft SQL Server\MSRS10_50.MSSQLSERVER\Reporting Services\ReportServer)
2. Comment the <RSWindowsNegotiate/> under <AuthenticationTypes> element.