Instructions
Insert the game's disc into your computer's optical drive, and double-click the "Warcraft III: Reign of Chaos" program icon to launch the game.
Click the "Options" option on the game's main menu.
Click the "Gameplay" option to open up the "Gameplay Options" menu.
Place a checkmark next to the "Enable Health Bars" option.
Click the "OK" button to save the settings. The health bars for your units will be displayed when you launch the "Defense of the Ancients" scenario.