X-COM: Complete Pack Minimum System Requirements:
Supported OS: Microsoft® 2000/XP/Vista®
Processor: Pentium II 233 MHz or higher with hardware acceleration, OR Pentium II 266 MHz or higher without hardware acceleration
Memory: 32 MB RAM
DirectX: 8.0 or higher
Sound Cards Supported: 1 MB Windows compatible sound card
Hard Disk Space: 500 MB


X-COM: Complete Pack Recommended System Requirements :
N/A

Activation on Steam

1)      Download & install the Steam client on your computer from   here.

2)      Open the Steam client, register and login. Then, locate the Games tab on the top menu. Click that and select “Activate a Product on Steam..”

       

3)      Enter your code that is showed on the orders page of eTail. Market and and follow the steps showed to activate your game.

       

4)      The game can be monitored now and you can see it on the "Library" section on Steam. You can download and install the game now.

5)      If you need more information and support, you can click here: https://help.steampowered.com/en/wizard/HelpWithSteam