SQL Server 2005 and SQL Server Express on the same machine?

Question

Can we have both version installed on the same computer?

Answer 1

Yes, you can even install SQL 2005 multiple times and multiple 2008 installs on the same computer.

Since quite some version SQL Server instances are named (with the exception of the default instance), and the express version has a defined different name.

Answer 2

yes, you can certainly. But you need to name the sql engine instance differently, such as sql express 2005 as sqlexpress2005, sql 2005 as sqlserver2005, sql server express 2008 as sqlexpress2008, sql server 2008 as sqlserver2008 etc.