We first uninstall firebird by opening the Microsoft Windows Control Panel. Then open Programs and Features. From here, we uninstall the following two programs.
1. Firebird 2.5
2. Firebird Database Updater
Now we reinstall firebird
Open C:\Multifocal\Firebird and Utilities
Double click Firebird Installer(v6).exe, or if that doesn't work try Firebird-2.5 file. There is a copy attached to this article for 64 bit computers.
You can click next through the whole installation process, no settings need to be changed.
After that is done, you may need to reconnect yo your database in Database manager in the Espion software.