OverbyteSrvDemo is using a Paradox file thru the BDE. Under Windows 7, you must
either run OverbyteSrvDemo as administrator (Not a so good idea) or configure BDE
so that it has the required permissions (Better idea). To configure BDE, see this 
article: http://www.willneumann.net/2008/09/configuring-bde-for-windows7/
Warning: If using 64bit Windows 7, the registry key to change is HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Borland

BTW: Midware is not dependent at all on BDE. I used a Paradox file because everyone
should be able to use it. If I used a database, then this would require the database
engine to be installed. Of course in your real applications, you will probably use
a SQL database (Firebird, MS-SQL, Oracle, Interbase,...) instead of BDE. In the 
demos, replace TQuery by the component you want to use to access your database.
I mostly use TAdoQuery because I can access many differents databases using the
same component. But this is just my preference.

--
Francois Piette