Article 3.6.1R : How to find the SQL Version (whether it is SQL Express or SQL Server).
Step 1 : Open SQL Configuration manager
Step 2 : Right click SQL server (SQLEXPRESS) > Properties
Step 3 : Go to advanced tab & scroll down.
Step 4 : Find "Stock keeping unit name"
Step 5 : It will show whether it is SQL Express edition or SQL server edition.