Now imagine, you have multiple SQL Server 2012 instances to install with the same configuration on the multiple servers and you want this task to be done as quickly and consistently as possible. When this is the case, you may choose the unattended installation option. SQL Server unattended installation option lets administrators install SQL Server on multiple machines with little or no user interactions. SQL Server 2012 unattended installations can be done using command line parameters or configuration files. All SQL Server step-up screen entries and the dialog responses are made automatically by using information stored in the configuration file or by command-line parameters.
This article shows you the steps to perform unattended installation of SQL Server 2012 on a Windows Server 2008 system by using command line and configuration file.