Unable to load DLL 'iclit09b.dll'

After I have setup the Informix server and the Informix client, I face the following problem when trying to run my ASP.NET application:

unable to load DLL 'iclit09b.dll': The specified procedure could not be found.
(Exception from HRESULT: 0x8007007F)`

Look where your iclit09b.dll is and add this directory to PATH environment.

You can use my simple Python "dll tester": http://code.activestate.com/recipes/576522-searching-dll-and-exe-files-in-path/

On my machine it gives:

c:\tmp>which_dll.py iclit09b.dll
2010-09-29 12:16:56      1004032 [b]    C:\informix\bin\iclit09b.dll
    trying to load "iclit09b.dll" ...
    C:\informix\bin\iclit09b.dll loaded

You can also try configure database connection using ODBC manager while iclit09b.dll is used by ODBC.