I think I had same error with Win7. Setup didn't find fbclient.dll. Copy it to somewhere in path (or modify path to include bin directory if Firebird).

I did a bit of digging and the code in fdb.ibase doesn't find the fbclient.dll if it is not in the path.

What about using the registry instead of 'ctypes.find_library'?

at around line 18:

elif sys.platform == 'win32':
    # use windows registry instead of find_library
    import _winreg as winreg
    import os
    baseKey = 'SOFTWARE\Wow6432Node\Firebird Project\Firebird Server\Instances'
    key = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, baseKey)
    instFold = winreg.QueryValueEx(key,'DefaultInstance')
    fb_library_name = os.path.join(os.path.join(instFold[0], 'bin'), 'fbclient.dll')
    #fb_library_name = find_library('fbclient.dll')

probably needs some improvement to handle 64bit server install and maybe others.

Above worked for me on Windows 8.1 with 32bit Firebird install.

Werner