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>