XCOM: Ultimate Collection Minimum System Requirements:
OS Version: Windows® 7, 64bit
Processor: 2.4 GHz Quad Core
Memory: 4 GB RAM
Graphics: 1 GB AMD Radeon HD 7770, NVIDIA GeForce 650 or better
DirectX Version: Version 11
Disk Space: 18 GB available space
Sound Card: DirectX compatible sound card

Additional Notes:
Initial installation requires one-time Internet connection for Steam authentication; software installations required (included with the game) include Steam Client, Microsoft Visual C 2012 and 2015 Runtime Libraries, and Microsoft DirectX. Internet connection and acceptance of Steam™ Subscriber Agreement required for activation. See www.steampowered.com/agreement for details.

XCOM: Ultimate Collection Recommended System Requirements :
OS Version: Windows® 7 64bit / 8.1 64bit / 10 64bit
Processor: 3 GHz Quad Core
Memory: 4 GB RAM
Graphics: 2 GB AMD Radeon HD R9 290, NVIDIA GeForce GTX 980 or better
DirectX: Version 11
Disk Space: 18 GB or more available space
Sound Card: DirectX compatible sound card

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