Hi,
I have never been a big fan of utilizing .sdf files to run an
application. I would suggest that you utilize SQL Server Express. It's
a fairly light running application, it will generally run on what
Windows 7 will run on. Also with SQL Server Express,
you can do something called Replication. This is an automated process
of updating a database to a stand set by a single DB.
I work for a large corpation with hundreds of client machines running
an application that needs to have the Stand Alone ability, this is what
we use. The only problem that we have is when the database doesn't
update for more than a week, this is generally
because the computer is off for a while. This issue is also one that
we have created for ourselves for several technical reasons.
Also, if you are building this as a web application, I would suggest
using a client type of application. Some like WPF or Win Forms.