This may sound simple but my program compiles and runs fine in debug mode, but when I change this to ''Release'' I get about 27 link errors like: d3dfile.obj : error LNK2001: unresolved external symbol _D3DXLoadMeshFromXof@28 They are all similar to this. What am I missing? Question 2: How do I use CString objects in DirectX programs, when I #include And use them like usual, I get a compile error telling me: fatal error C1189: #error : WINDOWS.H already included. MFC apps must not #include Error executing cl.exe. Any help appreciated