Are you trying to run "Hello world" for the first time? Please make sure you choose proper toolchain. For Windows you have to choose MinGW GCC.
To make MinGW GCC compiler as default or change you original project with error "Program “make” not found in PATH" or "launch failed binary not found eclipse c++" when you trying to run program simply go to Windows >> Preferences >> C\C++ Build >> Tool Chain Editor >> Change Current toolchain to MinGW GCC