Hi Again :

Tried this, it didn't work, it transfered the errors to the linker not the compiler.

Which means it has compiled. Now, what exactly are you using ? is there a static/dynamic library or a .c file for it? Have you written it yourself ? Essentially (without seeing the linker error...please send this if still unresolved) this is probably because of unresolved function declared in the header file but not found when you link. in as plain English as I can Master : When a function prototype is encountered eg. void func(int param); //no function body the compiler generates a 'lookup' (an 'entry point' reference to a function) to be filled in later (when it actually generates(compiles) the function in another .c file). Your output file(s) will contain calls to functions (obtained via prototypes) which need to be resolved in order to make a whole executable. The Linker will resolve by either a) matching the calls to a function defined in another output file or b) through a library that it is aware of. Therefore you need either a .c file which defines the function to compile (to make an output file) and link together with your main.c's output file. Or your linker needs to know where to find the library which contains the pre-compiled function. Add the directory containing the library to your linker options. If you have a .c file add it to your project as a new node (if using an IDE) or make sure it is in your source directory (if using a makefile which processes all files within the project tree) If still stuck, or this makes absolutely no sense then email me over the stuff you have, and/or your linker error messages and I'll have a look. HTH Cheers Earl