CS3/CS4/CS5 ME versions are no longer sold. You may find them on old installation disks or archives, but Adobe no longer supports activation for CS2/CS3/CS4. For legal use, consider Adobe Photoshop CC (with ME features enabled) or older legitimate CS6 ME copies (if you have a valid license key).

Once enabled, new options will appear in your and Paragraph panels specific to RTL languages:

: You can switch between Left-to-Right and Right-to-Left paragraph directions.

In modern versions, you no longer need a separate "ME version" installer. These features are built into the standard app. Set the Engine Edit > Preferences > Type (Windows) or Photoshop > Preferences > Type Select Layout : Under "Choose Text Engine Options," select World-Ready Layout Middle Eastern and South Asian in older CC versions).