Hi. I'm working in Keil ARM. There is a function 'File Extension, Books and Enviroment..'. Such tree box in icon, second incon in right to Select Target. There is something like Project Targets, Grups and Files. Could you tell me if in Files I should add source files .c (or .S for asm) or there should be header files (.h) included too? In some projects I saw only c files and in some there were h files too. Is there any rule for it?