Enabling Windows SDK 7.1 in Visual Studio 2008

I was having a problem where Visual Studio was saying that “windows.h” could not be found after having installed the Windows SDK v7.1. I found this article which said to update the path in “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SDKs\Windows\CurrentInstallFolder” in the registry. So I did that, and now everything is working.

Fatal error LNK1120: unresolved externals, caused by C functions in C++

I was receiving link error LNK1120 in Visual Studio after adding some C code to my C++ project, and the problem was, as I discovered here (and found more info on here), that I hadn’t declared my C code as “extern C”.

So basically I added #ifdef __cplusplus macros to check if it was C or C++ code and if C++ then outputting “extern C {” with a suitable “}” at the end of the file.