On linux: >From where does gcc picks up header files like stdio.h by default? Does it configure gcc to pick header files from particular location at the time of build? On windows: I copied cygwin directory from one of my friend's machine where cygwin was installed to my machine. however when i run gcc from windows command prompt i get an error displaying "stdio.h : no such file or directory. header files are already present in cygwin\usr\include. I have placed cygwin on the same location where it was present in my friend machine C:\cygwin. In my PATH , i have set C:\cygwin\bin . -- View this message in context: http://old.nabble.com/gcc-default-include-path-tp28068385p28068385.html Sent from the gcc - Help mailing list archive at Nabble.com.