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:
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