Error: 'als15.py' is not recognized as an internal or external command

[Alan Stewart]

Error message is the following:

'als15.py' is not recognized as an internal or external command, operable program or batch file.

The program code in 'als15.py' is Python code that has run before.

PLEASE. What does that mean and suggestions as to how I would fix it. THANKS. Alan Stewart

[bvdet]

At the command prompt, type in "python als15.py". The python executable must be in the system path or you must be in the same directory as python.exe. You may need to include the path to als15.py.