Under some situations you may come across an issue that requires you to delete and recreate the data sources for Reporting Services 2005 for your instance of TFS.  An example would be where you need to rebuild your server from a backup but for whatever reasons the SSRS encryption keys were not backed up themselves.  This post will detail how to recreate those data sources.

To confirm or change the details for the connection to the Data Tier from Reporting Services you need to follow these steps, as with most procedures of this nature you need to be logged in as the TFSSETUP user.

1. Connect to http://apptier/reports and you should see a page with a folder for each team project and two data sources:  TfsReportsDS and TfsOlapReportsDS

2. Click on TfsReportsDS and use the following settings:
   Connection Type: Microsoft SQL Server
   Connection String: Data source=datatier;initial catalog=TfsWarehouse
   Select "Credentials stored securely in the report server" and enter the credentials for the TFSREPORTS account
   Tick the "Use as Windows credentials when connecting to the data source" box
   Click the apply button then navigate to the home page

3. Click on the TfsOlapReportsDS data source and enter the same as above though ensuring the Connection Type is set to "Microsoft SQL Server Analysis Services"

If you followed the above you should be back up and running.

Jason