Use a tool like WinRAR or 7-Zip to extract the .rar file.

According to the official Steam page , the minimum requirements are: Windows 7 64-bit or later Processor: Dual-core Intel or AMD, 2.5 GHz or faster Memory: 4 GB RAM

Run setup.exe and follow the prompts to install the game.

NVIDIA GeForce GTS 450 or Intel HD Graphics 4600 or newer Storage: 5 GB available space Installation Instructions (Standard CODEX Procedure)

Open the resulting ISO file or mount it using a virtual drive.

Copy the contents of the CODEX folder (located inside the ISO) and paste them into the game's main installation directory, overwriting existing files. Play: Launch the game using the main executable. Save 80% on The Alliance Alive HD Remastered on Steam