How to add C++ project with two 3rd party unmanaged DLLs

[genesistr]

I have two 3rd party unmanaged c++ dll and one C++ project which uses these dlls. In my asp.net project i added c++ project as reference but in runtime it fails with that error:
Exception from HRESULT: 0x8007007E

Visual studio puts c++ project's dll into /bin folder auto. Even if i put other dlls into bin folder, it fails.

[Frinavale]

Did you register the DLLs using the regsvr32 tool?