> I have Firebird 2.1 server on Windows XP sp3 machine. Server is not 'installed', I use the zip distribution and start it with
> fbserver.exe -a (as application)
> This way, I can't connect to a local database specifying only a path like C:\test.FDB in the connection string - I get
> 'Unavailable database' error.
> If I use localhost:C:\test.FDB - no problems at all.
>
> On the same machine I also have Firebird 1.5. If I shutdown 2.1 and start 1.5 (again as application) - no problem. I can connect
> both as Local and via TCP.
> What might be the reason for this - the same database, same connection string, but it works for 1.5 and not for 2.1 ?
>
> I tried to put IpcName = FIREBIRD or IpcName = Global\FIREBIRD in firebird.conf file for 2.1, but it makes no difference.

You probably use two firebird.conf files - one for fb server (fb2.1), one for fb client library used by your application (fb1.5).
The IpcName values in both must match.

(of course you can't set the same IpcName value for both FB1.5 and FB2.1 servers if you want both to run simultaneously)

Ivan