Cannot Connect to an MS SQL Server

Hi,

I've developed an application that connects to an MS SQL server to read and write from a database. I have tested the program on about 6 computers (all on different networks and internet connections, etc...) and they can all access the database remotely just fine.

However, today I tried it on another PC (i.e. the 7th computer) and for some reason it won't connect. This computer is definitely on the internet as I can surf the web with it just fine, but every time I try to run the program it comes up and says that it cannot connect to the database. I can't remember the exact error message, but it was behaving as if the computer wasn't on the internet. What might cause a problem like this?

I did notice that this PC is running Norton Antivirus. All the other computers I tested on were not using Norton. Could Norton be the possible cause (i.e. might it be blocking a port or something like that). I will test it without Norton running, but I just thought I'd ask here too to see if anyone knows other possible reasons why this would be happening.

Thanks.

Have you tried to ping the IP/DNS name of the SQL Server machine?|||moving to SQL Server Data Access forum.|||

Yes. Norton Antivirus could be the cause of the issue. Try run your app with Norton disabled. I assume all your 7 machines are clients and the SQL Server is always the one.

One more thing you can check is to see if you have outdated alias defined on the 7-th machine. Use c:\windows\system32\cliconfg.exe or SQL Server Configuration Manager (if you app use sqlncli.dll) to check it.