Download the Express Edition. SQL Server 2017 Express is a free edition of SQL Server ideal for development and production for desktop, web, and small server applications.
To Install the software:
In the Downloads folder, double click the installation file that was downloaded, for example
When asked to select an installation type select Custom.
The next window asks you to specify the media download target area, accept the default location. Click Install to continue.
The installation software is downloaded into the default location. This may take a few minutes depending on the speed of your network connection.
When the Installation window opens select the option "New SQL Server stand-alone installation or add features to an existing installation".
The license Terms window opens. Tick the box "I accept the license terms" and then click Next.
The Global rules are checked then the Microsoft Update window opens, It is recommended that you select the option "Use Microsoft Update to check for updates". Click Next to continue.
The Install Setup files are run then the Install Rules window opens. If there are any rules that have failed you will need to rectify the problem. If the rules have passed or there is just a warning about the windows firewall, click Next to continue.
The Feature Selection window opens.
Click the button Unselect All.
Select the Instance Feature Database Engine Services.
Click Next to continue.
The Feature Rules are checked then the Instance Configuration window opens. Change the named instance from SQLExpress to Skyline. The Instance ID will be updated automatically. Click Next to continue.
The Server configuration window opens. Accept the defaults and click Next to continue.
The Database Engine Configuration window opens. The authentication mode Mixed needs to be selected.
Select the Mixed Mode (SQL Server authentication and Windows authentication).
Enter the password for the SQL Server system administrator account. The default Skyline password is SkylineH0$t.
Click Next to continue.
The feature configuration rules are checked and then the installation begins. The process can take a few minutes but when finished the Complete window opens. Click Close to finish the installation process.
You now need to install the SQL Server Management Tools.
At the Installation window select the option "Install SQL Server Management Tools"