> Hello Group,

> Is it possible to take a backup of a 2.5 database whilst it is running in embedded mode (Windows) and whilst that application is otherwise
> connected to the database using the services manager (just like you can on the full server)?

  Sure

> I am presently getting an exception that the database is opened by another engine instance but process explorer only identifies my
> application as having a handle to it.

    Sooner of all that another instance run at another windows session (by another user). In this case windows security model makes
named kernel objects (such as events, MMF's and so on) "private" within the session and not accessible from another session. It not
allows Firebird engines (hosted by user applications in different sessions) to coordinate with each other.

    Make sure you run PE with elevated privileges to see processes at another sessions.

Regards,
Vlad