Hi, I have written an MFC dialog based application that is using completely separate header files and I am getting 3 errors that will not budge.

error LNK1120: 1 unresolved externals c:\users\luke\documents\visual studio 2012\Projects\Bugs\Debug\Bugs.exe 1

error LNK2001: unresolved external symbol "public: int __thiscall CRegistry::LoadKey(wchar_t const *,wchar_t const *,class ATL::CStringT<wchar_t,class StrTraitMFC_DLL<wchar_t,class ATL::ChTraitsCRT<wchar_t> > > &)" (?LoadKey@CRegistry@@QAEHPB_W0AAV?$CStringT@_WV?$StrTraitMFC_DLL@_WV?$ChTraitsCRT@_W@ATL@@@@@ATL@@@Z) c:\Users\Luke\documents\visual studio 2012\Projects\Bugs\Bugs\VersionTranslatomatic.obj

error LNK2019: unresolved external symbol "public: int __thiscall CRegistry::LoadKey(wchar_t const *,wchar_t const *,class ATL::CStringT<wchar_t,class StrTraitMFC_DLL<wchar_t,class ATL::ChTraitsCRT<wchar_t> > > &)" (?LoadKey@CRegistry@@QAEHPB_W0AAV?$CStringT@_WV?$StrTraitMFC_DLL@_WV?$ChTraitsCRT@_W@ATL@@@@@ATL@@@Z) referenced in function "public: __thiscall CSmartSEMOEMBranding::CSmartSEMOEMBranding(struct HWND__ *)" (??0CSmartSEMOEMBranding@@QAE@PAUHWND__@@@Z) c:\Users\Luke\documents\visual studio 2012\Projects\Bugs\Bugs\SmartSEMOEMBranding.obj

any help would be appreciated.

Where did CRegistry come from?

CRegistry comes from a separate header file named Registry.h.

You need to add Registry.cpp to your project. I take it it originally came from here.
http://www.codeguru.com/cpp/w-p/system/registry/article.php/c2877/A-Class-For-Handling-The-Registry.htm