By default the remote MS-SQL server connection not enabled once you have installed in your system, We can enabled in few steps,
Step 1 : Go to Start -> Programs -> Microsoft SQL Server 2xxx -> "SQL Server Configuration Manager"
Step 2 : Then, Select "SQL Server Network Configuration" on Tree View left panel You will see "Protocol for SQLEXPRESS"
Step 3: Double click on "Protocol for SQLEXPRESS" You can see protocol name and the status (Enabled/Disabled)
Step 4 : Right click on "TCP / IP" protocol and click on "Enabled" and go to "TCP/IP" properties. For example refer the below image.
Step 5 : Scroll down to "IPAll" place need to sure TCP Dynamic Ports is blank also the TCP Port is set to 1433,
Step 6 : Fianlly Click on "OK" buttton.
Now, you can easily access your mssql database in your system from the Server.