I have an end user with SQL Server 7 and it has been working fine. Apps
connect to it through ODBC, including on the system running SQL Server.

They installed some address book program on the system running SQL Server
and after that, the ODBC data source could not connect to the server (on the
same machine), getting an HYT00 - timeout error. Other users could connect
to SQL Server however.

After playing around with it, I found that changing the server in the ODBC
data source from "(local)" to "." allowed the system to connect to itself.

What possibly could have changed to make "(local)" stop working?

Note: I ran the Network Utility from the BINN directory (svrnetcn.exe) and
it showed that Named Pipes was selected, but Shared Memory was grayed out.

Hi JJ:

From your description, there may be a rogue DBLIB application orphaning thousands of
connections and makes the connection "time out". It seems that the address book program
you mentioned is the right culprit.

It's my pleasure to provide your some possible answers to you question: "What possibly
could have changed to make "(local)" stop working?" I'm not sure enough because many
reasons can be concerned in this issue, but the following causes will do make the issue occur:
1. (Local) might be not parse as 127.0.0.1
2. Net Bios issue can also be considered
3. The address book program makes some changes in Registry on the key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer
4. The program changes the protocol settings between client and server

Although the problem is weird and the ROOT cause is uncertain, I still provide some
suggestions to try:

1. Make sure the Client and Server use the same protocol. In Client Network Utility,
enable TCP/IP the first priority (On TOP). In Server Network Utility, enable TCP/IP.
2. Use localhost and 127.0.0.1 to connect
3. Use SQL Server's IP address to connect
4. Use SQL Server Alias to connect
a) In SQL Server Client Network Utility -> Alias, Click Add and enter the Alias and Server
Name. Left the rest default and click OK
b) In ODBC, use the Alias you create above to connect
5. Uninstall the address book program
6. Apply SQL Server 7.0 SP3 and the latest Service Pack of you Operating System

Please apply the suggestions above and let me know if my suggestion helps you resolve the
problem. If there is anything more I can assist you, please feel free to let me know.

Thank you for using MSDN Newsgroup!

Kind Regards,
Billy Yao
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "as is" with no warranties and confers no rights.

JJ:

Please also send me the SQL Server ERRORLOGs in C:\MSSQL7\LOG.

Thanks in advance,
Billy