Is there a way to reset a SQL Server Express 2008 to it's initial configuration? Maybe re-creating the instance?
No, there's not a way to reset SQL Server Express to the default configuration and data.
Your best bet would be to uninstall Express and reinstall it.
Without providing more information on what you have changed its hard to answer your question properly.
You may want think about joining a SQL community to help you with your learning.
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