dll not loading- FileLoadException

The problem I am having is that I am getting a System.IO.FileLoadException when trying to load the RWLock.dll on a test box and Windows xp machines.

This is the exception that is thrown when it tries to load the dll on the windows 2003 server machine (most likely 32 bit):

System.IO.FileLoadException: A procedure imported by 'rwlock, Version=1.0.3889.27926, Culture=neutral, PublicKeyToken=null' could not be loaded.

File name: 'rwlock, Version=1.0.3889.27926, Culture=neutral, PublicKeyToken=null' ---> System.Runtime.InteropServices.COMException (0x8007007F): The specified procedure could not be found. (Exception from HRESULT: 0x8007007F)...

However, we have not had any problems trying to run this on a Windows 2007* server machine (64 bit).

Any ideas? Thanks in advance :)

*windows 2008(oops)

The error message is telling you that RWLock.dll tries to import a function that doesn't exist from another DLL. This probably means that RWLock is trying to import an API function that exists on the (I presume you meant instead of "Windows 2007 Server") Windows 2008 Server machine, but not on Windows 2003 or earlier.

You can use Dependency Walker to figure out what it's trying to load and where it's trying to find that missing function, but it won't help make it available on the Windows versions where it doesn't exist.

The other possibility is that RWLock has a dependency on another DLL that it provides, but you're not re-distributing it properly. Dependency Walker can help with this, too.