To test your vendor’s suggestion, you can disable the Named Pipes protocol for the affected server. To do so, log into the server, run the Configuration Manager. (Start>> All Programs>> SQL Server 2005>> Configuration Tools>> SQL Server Configuration Manager) Expand the SQL Server 2005 Network Configuration tree, then click on the instance to which you are trying to connect. In the right pane, you should see Shared Memory, Named Pipes, TCP/IP, and VIA. If Named Pipes is set to “Enabled” simply right-click and “Disable.” For this to take effect you will need to restart the SQL Server service. This will allow you to at least test if Named Pipes is indeed your issue.
If you still have problems after this, post the error messages, and it will help point to what the real problem may be.