Problem with connection to Informix 7.21(BDE 4.0), HELP

I got big problem with connection to Informix 7.21.
I created Alies, but after trying to connect i receive error
"Cannot load an IDAPI service library.File SQLINF32.DLL."
This file exists and located in PATH enviroment. May be dll was corrupted
in install package ?

Please help me solve this problem.