MS SQL server name and instance name

Open the run command and type "sqlcmd" and press enter will open the related console and to get the server name and instance name, enter the following command in the command prompt

select @@servername
go

Also, connection string can be verified by entering the following command in the 'Run' window from windows start

sqlcmd -S Server\Instance

where server is the name of the server running Sql server and Instance is the name of the instance running on the server.

Refernce: How to: Identify a SQL Server Express Instance