The ReportServerVirtualDirectory element is missing

Install SQL Server 2005 on a Windows Server 2008, when use your browser to access http://localhost/reports, you received below error msg:
"An error occurred while parsing the configuration file. The ReportServerVirtualDirectory element is missing. "
After doing some search&research, this is the workaround.

Lookin the RSWebApplication.config for the "<ReportServerVirtualDirectory>"

It will look something like this

<ReportServerVirtualDirectory></ReportServerVirtualDirectory>

change to

<ReportServerVirtualDirectory>ReportServer</ReportServerVirtualDirectory>