KB133250 - Unable to connect to SQL Server if default protocol Is changed

SYMPTOMS

When you change the default network protocol in the SQL Client Configuration Utility, one of the following error messages appears in the SQL Server Administrator or Systems Management Server Administrator program:

Error message 1

Unable to connect: SQL Server is unavailable or does not exist. Specified SQL Server not found.

Error message 2

Couldn't connect to server <server name>.

Additionally, after changing the default network protocol, Setup may fail, with the following error message in the Smssetup.log when upgrading from Systems Management Server 1.0 or 1.1 to version 1.2:

<mm-dd-yyyy hh:mm:ss> Registering connects for XXXXXX (server name)
sa (default value)
SMS (default value)
<mm-dd-yyyy hh:mm:ss> Registered the types
<mm-dd-yyyy hh:mm:ss> Upgrade thread: Failed to register SQL connection
types.

RESOLUTION

Run the SQL Client Configuration utility.

Click the Net Library tab.

Do one of the following:

Click Named Pipes as the default network for the net library configuration.

By default, SQL Server is configured for named pipes.
Click the Alias tab, click Add, type the server name of the SQL server that contains the SMS database, and then click Named Pipes as the net library. Then, click OK.