Hi,
I tried running the same example as Ray did, using io.h and a simple c file with WinMAin. My project builds without errors as well. I would definitely check out any previous declarations you might have made for wchar_t. In addition, I would try making a new project and recreating the test Ray and I did to see if the error persists in your code. If it works ok, then I would go back and recreate your project piece by piece to find that redeclaration.
Hope this helps!
Jeremy L.
National Instruments
Jeremy L.
National Instruments