You need a running Firebird server in order to access your database. If you just want to access the data, then the easiest way would be:
- Grab free FDBConvert utility and upgrade database to the Firebird 2.5 format
- Install Firebird 2.5 server. Get setup from here. Use Win32 version if your GUI tool is 32 bit application. During installation check "Generate client library as GDS32DLL for legacy app support?".
- Make sure that Firebird service is running and try to connect to the database.
If the database will be accessed by an old application later on, then you have to:
- Determine Firebird version needed. Use gstat -h dbname.fdb command. Check ODS version value. In the table here you will find a correspondence between ODS number and Firebird version. gstat utility is a part of server installation.
- Download and install appropriate version of Firebird server from here.