Find SQL Server instances on local network

on command prompt: run

c:\ > osql -L


another way is to run from powershell, open "powershell ise" and run as administrator

now run command

[System.Data.Sql.SqlDataSourceEnumerator]::Instance.GetDataSources()

it will give information as following

ServerName InstanceName IsClustered Version
---------- ------------ ----------- -------