Note: If you already have AMPPS 4.x version installed you can directly update to the latest version by click on Update AMPPS button AMPPS UI.
Note: If you have recently installed older version of AMPPS and do not have any important data then please Uninstall AMPPS 3.x and install latest version AMPPS 4.x as that will be the fastest way.
Note: Please take a note of MySQL version before update.
NOTE: If your previous MYSQL version is less than 5.7 then you have to manually import database SQL files using Import functionality of phpMyAdmin and create database users manually. You should skip step 3 and 4.