When you install Microsoft SQL Server the install generates a configuration file. This is great if you want to create an unattended install of SQL. If you want to do a second install (or third or fourth…) just run: 

Setup.exe /ConfigurationFile=ConfigurationFile.INI

and you get the same install again.

Today I wanted to do the same with SQL express… but no file was created… Hmmm…

Apparently you need to start the install using this:

Setup.exe /ACTION=INSTALL /UIMODE=Normal

/Johan

Links

http://www.codeproject.com/Questions/713204/SQL-Server-How-to-generate-a-configuration-fi