At 06:35 PM 8/04/2008, you wrote:

>Hi,
>I had installed firebird 2.0.3, then uninstalled it.
>Then I had installed firebird version 1.5.0.4306.

Why? That version is almost five years old. You should install v.1.5.5.

>The installation
>was complete successfully, and the service is running. But when I
>tried to connect to this DB from Borland C++ program, I received an
>error:
>isc_unavailable.
>
>At the log there is an entry like this:
>D-21906 (Client) Tue Apr 08 08:43:54 2008
> Control services error 1061

This probably means that you tried to connect to a database before Windows had finished starting the Firebird service or another service that Firebird depends on, such as TCP/IP.

>the lines of code are:
> m_pDatabase->DatabaseName = FullDatabaseName;
> m_pDatabase->Params->Clear();
> m_pDatabase->Params->Values[IB_USERNAME] = m_UserName;
> m_pDatabase->Params->Values[IB_PASSWORD] = m_Password;
> m_pDatabase->Connected = true;
>
>* before upgrading to 2.0.3 and downgrading again, it worked ok.
>also - I have external tool to DB which works ok.
>
>what could be the problem?

If indeed you are using IB Objects then don't use Params directly. Instead, use the Server, Protocol and Path properties and fill the DatabaseName property with an internal friendly name.

If you don't use IBO then you are off-topic here. We can only guess what FullDatabaseName might be...but you will have to tell us more about the server model you are using (Classic or Superserver) PLUS exactly what the whole string is that the client is using to connect.

There are other possibilities that might have snafu-ed your Firebird installation, for example installing over the top of a running service, which has lately proven to be possible, due to a bug in the Windows server executables (both Fb 2.0.3 and all the Fb 1.5 series); or trying to open an ODS 11 database from a Fb 1.5 server.

Helen