Yes, you can.  It just requires a different instance name than the other
installed instances.

We are running a Windows 2003 domain.  I have a Windows 2003 member server
running an app. and MSDE.

I now have another app. that I would like to install on this same server.
The new app. also needs MSDE.  My question is can I install and run more
then one copy of MSDE?  Is there anything I need to know about doing it?

TIA,

Clayton

Or can I just use the same MSDE for the new app.?  Can MSDE have more the
one DB?

TIA,

Clayton

You can install up to 16 instances of MSDE (I think that is still
correct -someone correct me if I'm wrong.) on the same server.

However, each additional instance will have a variation in the instance
name. For example, if your server is MyServer, the first installation of
MSDE (or SQL Server) will be know as MyServer. When you install a second
instance of MSDE, you are required to provide an 'instance' name (e.g.,
Accounting). Then that server/instance will be referred to as
MyServer\Accounting. You have to use the compounded name in all connection
strings, etc.

That may not be a simple issue for many third party applications. (I would
hope so -but I've learned to be pessimistic about the skills of a lot of
programmers.)

[Loud retort from over my shoulder ="Hey, I represent that remark!"]