Ok this is kinda hard to explain. Im working on a project for shcool that requires me to alter some of my teachers code to some simulation models enable it to run under windos, no problem doing that. The problem is that he created a .lib with the implementations of the base classes in the lib. Now with the derived classes im trying to stuff them into a generic DLL so that I can have the app load any of the models the same way. I got the code to compile with no errors or warnings, but when I go to link it gives me 3 unresolved externs which are in the lib and I have no access to the code for the lib. Oh and his lib uses classes no C style functions.