Quote:I wrote a simple Windows Form application

You created a Windows Forms Application from the CLR tab. You should be creating a Win32 Console Application or Win32 Project under the Win32 tab.

I just tested using a CLR project and got the same results as you did with OutputDebugString failing to output. I don't know why that's the case, but it works under normal Win32 projects just fine. I would suggest you recreate your project as a Win32 Console project unless you are intentionally wanting to use a CLR styled project (which I would think you aren't after that at this point).