This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
The standard SQL server connection error (socket based) checklist includes...
- is the server where you think it is (have you specified the right host) - is there a firewall anywhere that is eating this (previously suggested but check for firewall problems on all of the client, the server and any network device in between) - is SQL Server set up to listen for TCP connections? (by default SQL server listens for named pipe connections only and these will largely not work and I am pretty sure never work with that driver) - is SQL Server set up to listen on the default port or another one that you need to specify?
Please note that if you need to enable TCP connection mode you need to restart the service. This isn't entirely clear in the docs but for versions I have worked with if you don't restart then that change does not actually take effect.