This is really a top annoying problem, the constant prompt for credentials each time you open a report. All you need to do is disable the Internet Explorer Enhanced security on the reporting server. This is done by running Add/Remove programs, Add/Remove Windows Components. In Windows 2008 you will find the setting in Computer Management, Security Information, Configure IE Esc.

image

Deselect the checkmark in Windows 2003 and you can start running your reports without the prompt 🙂

image

image

Select Off in Windows 2008.