To download and run on a modern PC, you should use the OpenXcom engine , as the original 1994 release has significant bugs and compatibility issues with modern Windows. 1. Purchase and Download the Base Game
GEODATA , GEOGRAPH , MAPS , ROUTES , SOUND , TERRAIN , UFOGRAPH , UFOINTRO , and UNITS . 3. Basic Gameplay Guide X-COM: UFO Defense Download PC Game
: Navigate to your original game's installation folder (e.g., SteamLibrary\steamapps\common\XCom UFO Defense\XCOM ). Copy the following folders into the /UFO/ subfolder of your new OpenXcom directory: To download and run on a modern PC,
: Unzip the OpenXcom files into a new folder on your computer. you should use the OpenXcom engine
XCOM UFO Defense: Walkthrough/Strategy Guide - Steam Community
You must own the original game files because OpenXcom requires them to run.