I managed to find a solution to my problems after lots of looking about...
Interbase Express has a component called TIBSecurityService which lets me
add, modify and delete users.

Sorry for not finding this sooner, thanks for the help.
Stephen

----- Original Message -----
From: "Fidel Viegas" <fidel.viegas@...>
Sent: Friday, August 29, 2008 6:59 PM
> On Fri, Aug 29, 2008 at 5:58 PM, Stevio <redeagle@...> wrote:
>> Even if I did that, I still have the problem that the end user may not
>> have
>> installed Firebird in the default location, or they may be using a
>> different
>> version of Firebird and so the path to where GSEC is will not always be
>> the
>> same.
>>
>> In the example above, my batch file contained this:
>> c:\Progra~1\Firebird\Firebird_1_5\bin\gsec -user SYSDBA -password
>> masterkey -add MYUSER -pw %myusername%
>>
>> How can I call GSEC from a batch file without knowing where it is? It is
>> not
>> in the command line path by default.
>
> You always create an environment variable for Firebird. Something like
> FIREBIRD_HOME=c:\Progra~1\Firebird\Firebird_1_5, and in your batch
> file you do something like this:
>
> %FIREBIRD_HOME%\bin\gsec -user SYSDBA -password masterkey -add MYUSER
> -pw %myusername%
>
> That way, if you change the default location, then you only need to
> update your environment variable.
>
> Another solution is to include your Firebird\bin into your PATH. That
> way, you only need to call gsec as opposed to the full path.