This is likely a Visual Studio issue but figured this is an obvious rookie error so someone will set me straight right away! I have loaded a sample project and compiled and run it properly on my hardware development kit; I can debug and all is good. However, the 'main.c' file that was provided contains a lot of stuff that I would normally expect to see in a 'main.h' file (which wasn't included as part of the sample). I created the main.h file and added it to the same folder as main.c and the intelisense cannot find it if I use "#include <main.h>". However, if I instead include the entire Windows directory path with the file name, then it works OK. How is the system not seeing the file since it is clearly in the project directory?