Ok, so I have this DLL that was written in VB that I need to use in a C++ Windows Service.<BR><BR>From what I have looked up, I need three things.<BR><BR>- A header file<BR>- the .lib file<BR>- the ...

You probably need to declare area() as PASCAL calling convention and with the EXPORT macro so that it is, indeed, exported from your DLL. You'll also have to defeat C++ "name-mangling", so define it ...