Symptom: reports work from the server. They do not work from client machines. "An error has occurred during report processing. (rsProcessingAborted). Cannot create a connection to data source 'MyData'. (rsErrorOpeningConnection). For more information about this error navigate to the report server on the local server machine, or enable remote errors."

Step 1: Set the server as trusted for delegation

• Active Directory Users and Computers
• Right-click SSRS Server, Properties
• Delegation tab
• (o) Trust this computer for delegation to any service (Kerberos only)

Step 2: Enable the service account to impersonate

• Check the service account
• Microsoft SQL Server 2005 > Configuration Tools > Reporting Services Configuration
• Windows Service Identity
• Web Service Identity
• SSRS is generally running under Network Service (NT Authority\NetworkService)
• Set the permissions
• Administrative Tools > Local Security Policy
• Add Network Service to: Act as part of the operating system; Impersonate a client after authentication 

 Step 3: Add the service principal name (SPN) for web services

•  Install Support Tools
• List the active SPN
• CD C:\Program Files\Support Tools
• Setspn -L SSRSServer
• If HTTP SPNs do not exist, add them.
• Setspn -A HTTP/SSRSServer SSRSServer
• Setspn -A HTTP/ssrsserver.mydomain.com SSRSServer

 Step 4: Add the service principal name (SPN) for databases

•  Check the service account
• Check to see what service is running "SQL Server (Instance)"
• Microsoft SQL Server 2005 > Configuration Tools > SQL Server Configuration Manager
• SQL Server 2005 Network Configuration
• Protocols for Instance: TCP/IP
• Scroll to the bottom, IPALL
• TCP Dynamic Ports: 3418
• setspn -L DOMAIN\serviceaccount
• If MSSQL SPNs do not exist, add them
• setspn -A MSSQLsvc/SSRSServer:port DOMAIN\serviceaccount
• setspn -A MSSQLsvc/ssrsserver.mydomain.com DOMAIN\serviceaccount

 Step 5: Modify the Data Sources

• http://ssrsserver.mydomain.com/Reports
• Data Sources
• Edit the data source
• Connection string: Data Source=ssrsserver\instance;Initial Catalog=MyDBname;Integrated Security=SSPI
• (o) Windows integrated security

From the desktop, open SQL Server Management Studio. Create a new connection

• Server type: Reporting Services
• Server name: http://ssrsserver.mydomain.com/ReportServer
• Authentication: Windows Authentication
• Click Connect and it will now open up reporting services.