How to write Java with Notepad - Compile and Execute with Command Prompt

This video shows how you can write your first program in JAVA with Note Pad (Free software comes with Windows installation)

Manually compile and execute the program with Command Prompt!

[johnoluwaseun]

When I try to compile using javac it's says file couldn't be found . I have the same problem with my intelliJ idea if I try to compile using javac with the terminal it says "javac isn't a known ...