C++ 'a.out' not recognised as a command

Hi all, 

I'm new hear and very new to coding. Just setting out on my learning journey to be honest. I'm hoping someone will be able to help. 

I've set up my C++ environment and was about to start learning and practicing, following the Tutorials Point tutorial. 

I created my first helloworld.cpp file, used g++ to convert it to an executable file and then followed the tutorials next instruction which was type 'a.out' to execute the file. When I do this, it gives me the error: "a.out is not recognized as an internal or external command, operable program or batch file"

I've typed the error into google and followed some instructions but none have helped me to fix this issue. In fact, I couldn't see any other mention of this exact error.  

I am in the correct directory and have added the bin subdirectory to the Path environment variable.

Please could somebody help? 

Thanks in advance