Open your start menu, right click "Computer" and hit "Properties." On the left side look for "Advanced system settings" and click that. There will be a button on this popup that says "Environment Variables," click it. Add a "New..." environment variable. Put the name as "PATH" and the variable value wherever you installed GCC. Once you do that it will recognize those commands.
Alternatively, download an IDE such as Code::Blocks or Visual Studio. If there's no specific reason for using command line GCC, then don't. Unless you like doing things the hard way.
Edit: Just saw your edit. Let us know how it goes.

Thanks for help guys)) After adding "PATH" cmd started gcc