The information in this posting is superseded by the following KB Article:
914277 How to configure SQL Server 2005 to allow remote connections
http://support.microsoft.com/default.aspx?scid=kb;EN-US;914277
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Some people have been having issues when trying to make remote connections 
 to SQL Express.  This document will hopefully clarify most of the issues 
 around remote connections.
 First, networking protocols are disabled by default in SQL Server Express. 
 Thus, if someone simply installs Express and chooses all the defaults, SQL 
 Server Express will only be able to have connections originating on the 
 local machine where SQL Server is installed.
 To enable SQL Server Express to accept remote connections we need to perform 
 the following steps:
STEP 1: Enabling TCP/IP
 First we must tell SQL Server Express to listen on TCP/IP, to do this 
 perform the following steps:
 1. Launch the SQL Server Configuration Manager from the "Microsoft SQL 
 Server 2005 CTP" Program menu
 2. Click on the "Protocols for SQLEXPRESS" node,
 3. Right click on "TCP/IP" in the list of Protocols and choose, "Enable"
 
STEP 2: To Browse or not to Browse
 Next, we have to determine if we want the SQL Browser service to be running 
 or not.  The benefit of having this service run is that users connecting 
 remotely do not have to specify the port in the connection string.  Note: It 
 is a security best practice to not run the SQLBrowser service as it reduces 
 the attack surface area by eliminating the need to listen on an udp port. 
OPTION A: If you want to always specify a TCP port when connecting (Not
 using SQL Browser service) perform the following steps else skip these 
 steps: 
 1.      Launch the SQL Server Configuration Manager from the "Microsoft SQL 
 Server 2005 CTP" Program menu 
 2.      Click on the "Protocols for SQLEXPRESS" node 
 3.      Click on the "TCP/IP" child node 
 4.      You will notice an entry on the right panel for "IPAll", right click 
 on this and select, "Properties" 
 5.      Clear out the value for "TCP Dynamic Ports" 
 6.      Give a TcpPort number to use when making remote connections, for 
 purposes of this example lets choose, "2301" 
 At this point you should restart the SQL Server Express service.  At this 
 point you will be able to connect remotely to SQL Express.  A way I like to 
 check the connection is my using SQLCMD from a remote machine and connecting 
 like this: 
 SQLCMD -E -S YourServer\SQLEXPRESS,2301 
 The "," in the server name tells SQCMD it's a port. 
 So you've tried this and still get an error.  Take a look at Step 3, this 
 should address the remaining issue. 
OPTION B: If you want to use SQL Browser service perform these steps:
            Note:
            You will need to make this registry key change if you are using the April 
             CTP or earlier versions:
            To enable sqlbrowser service to listen on the port 1434, the following 
             registry key must be set to 1
             HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\90\SQL 
             Browser\Ssrplistener 
Next, restart the sqlbrowser service.
 
       1. Start the SQL Browser Service 
STEP 3: Firewall..?
       At this point you should be able to remotely connect.  If you still 
 can't chances are you have a firewall configured on the computer where SQL 
 Express is running.  The instructions below are for Windows XP SP2's 
 firewall settings. 
       To enable the firewall to allow SQL Server Express traffic: 
 1.      Launch the Windows Firewall configuration tool from the control 
 panel. 
 2.      Click the Exceptions Tab 
 3.      Click the "Add Programs." button and select "sqlservr.exe" from the 
 location where you install SQL Server Express 
 You should be able to remotely connect.  Note, you can get more restrictive 
 by just specifying the port number that will be allowed (used best when 
 configured with Option A). 
 Note: If you chose to use the SQL Browser service, you must also add 
 sqlbrowser service executable to the exception list as it listens on udp 
 port 1434. 










