Hide SQL Server Instance in SQL Server 2000 and SQL Server 2005

To hide SQL Server 2005 Instance

In SQL Server 2005 you can hide a specific instance while other instance continue to expose. To hide a instance steps are as follows
1. Open SQL Server Configuration Manager from Prgramfile – Microsoft SQL Server 2005 – Configuration Tool
2. In SQL Server Configuration Manager, Expand SQL Server 2005 Network Configuration,
3. Right Click on “Protocol for ” and select properties
4. In Flag pane , you can find HideInstance with No set. Change No to Yes.
5. No need to restart the service, when you pressed OK, the new setting is immediately applied and new connection will not be able to connect to the instance using SQL Browser Service. You can still connect to the instance by specifiying protocol , Server name/IP address and port number or the named pipe directly

To hide an instance of SQL Server 2000:

1. Open the SQL Server Network Utility.
2. Select the instance that you want to hide. (This is only available on SQL Server 2000 instances). 3. Select TCP/IP from the list of enabled protocols.
4. Click Properties.
5. Select the Hide Server check box.
6. Click OK.
Note : Hide Server Option Cannot Be Used on Multiple Instances of SQL Server 2000
Refer :http://support.microsoft.com/kb/308091