When setting up a server, we installed SQL Server 2008. Now it turns out we don't need it, and we want to use the free Express version instead. Ideally without much interruption to things using the database. Is it possible to install Express side by side with the full version without disrupting things?
The tables are small and the load is relatively light. As in, there are maybe 30 rows in each table, and a few aspx pages that use them to keep track of state. We're not doing anything other than simple queries on a few tables in our current setup. I could get by using SQLite, if I wanted to rewrite some ASP.NET pages to use it.
Best Answer
As Shark already pointed out install or downgrade are distinct actions:
Any operation involving the live instance means it will interact and stop with the current instance. Some planning questions are in order now:
At first you need to answer all these questions and only then see what your options is.
EDIT: after all your details specified, I'd suggest you to install a new version along with the current working one. Then stop the working instance service, ATTACH the database files to the Express Edition, then move on with the uninstall of the other instance. This will make the database unavailable only for the attach operation.