The Report Server cannot connect to the Report Server database.

The Report Server cannot connect to the Report Server database. All requests and processes require a connection to the database. (Rsreportserverdatabaseunavailable) An error occurred while establishing a connection with the server. When you connect to SQL Server 2005, the default setting does not allow remote connection to SQL Server may cause this failure. (Provider: named pipeline providesProgram, Error: 40-unable to open the connection to SQL Server)
 
 
Solution:
Run
C: "Documents and Settings" XXX> rsconfig-C-s (local)-D reportserver-a SQL-U sa-P SA
Specifies the correct username and password for logging on to the database.

Rsconfig command parameter explanation:
The parameter after-s indicates the name of the sqlserver instance;
-D indicates the database connected to the report service, usually reportserver;
-A indicates the authentication method, windows or SQL. If the value is windows, the Report Server is used to connect to the database of the Report Server.