SSRS - SSRS Prompts for Credentials Again and Again If Access From Other Computer

Scenario: 

I have installed SQL Server 2008 R2 and configured Reporting Server. When I log in to Server, I am able to access reports but when try to browse the reports from other computer/s, It prompts for User Name and password again and again. After trying 3,4 times it shows nothing or display 401 error.

Solution : 

The quick solution for this is to remove  or comment from rsreportserver.config file that you can found most of the time under C:\Program Files\Microsoft SQL Server\MSRS10_50.YourInstanceName\Reporting Service\ReportServer

If you have installed your SQL Server to different Directory then try to find there.

For more details , please visit below link
http://msdn.microsoft.com/en-us/library/cc281253.aspx#proxyfirewallRSWindowsNegotiate