Unable to load DLL (Module could not be found HRESULT: 0x8007007E)

From what I remember on Windows the search order for a dll is:

1. Current Directory
2. System folder, C:\windows\system32 or c:\windows\SysWOW64 (for 32-bit process on 64-bit box).
3. Reading from the Path environment variable

In addition I’d check the dependencies of the DLL, the dependency walker provided with Visual Studio can help you out here, it can also be downloaded for free: http://www.dependencywalker.com