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

 Solution :-

set path=C:\Program Files\Java\jdk-11.0.13\bin

set JAVA_HOME=C:\Program Files\Java\jdk-11.0.13\

C:> jar

Usage: jar [OPTION...] [ [--release VERSION] [-C dir] files] ...

Try `jar --help' for more information.

To create jar file

jar -cvf C:\myJars myFolder

jar -cf C:\myJars myFolder

c is create

f is folder

v is verbose.