What is the instance name of MSSQL on the local server?
As of April 5th, 2012, the instance name of the MSSQL 2008 server depends on the server you are on. The majority of our clients setup previous to this date on any of our Windows accounts will be on an instance called "SQLEXPRESS". Most new customers will be setup on an instance called "MSSQLSERVER". For those on the MSSQLSERVER instance, excluding the instance name in connection strings should work. This is good information to have when trying to connect to the specific instance locally when the instance was not installed as the Default Instance on the server. Please refer to the knowledgebase article on classic ASP connection strings in the ASP .NET category for more information.