How do a run a c++ executable without a compiler?

You're jumping ahead of yourself. First you need to decide what compiler and possibly framework you want to use. Then you can find out what files (dependencies) need to be distributed with your program. Or what is required on your friends computer. To give you an example I'm developing some software in Qt framework (C++) and compiling with mingw compiler. I need to distribute 3 mingw .dll files + a couple of Qt package files for the program to be able to run on another windows machine (that doesn't have Qt and mingw installed). On the other hand if you're using .NET then the user will need the .NET framework runtime installed (a bit like requiring the java runtime installed to run java programs). So my advice is choose what compiler/IDE/framework you are going to use, and only then find out how to go about distributing. And bear in mind that you will only know for certain if your program works right on another machine until you actually test it on another machine.