Q:

Install SQL Server 2005 after installing 2008?

I installed Visual Studio 2010 and must have glossed over some of the details.  As a result, it upgraded my SQL 2005 Express Edition to SQL 2008 and migrated all my databases.
Is it possible to reinstall the 2005 engine without uninstalling 2008?  I'm happy to use 2008 tools to manage the 2005 databases.

A:

Yes, you glossed over the part where it installs SQL Express ;)
2005 and 2008 can live happily together next to each other.  You can only have one default instance of SQL Server, though, so if your SQL 2005 install held the default instance then it's probably been upgraded by the 2008 install.
You can run the SQL 2005 installer and reinstall SQL 2005.  You'll have to restore your databases from backup, though.  The database formats are incompatible between 2005 and 2008.

