Codex fails to start on Windows with CPU capability error (requested: 0x20000000)

Resolved 💬 2 comments Opened Feb 26, 2026 by CodenameCookie Closed Mar 4, 2026

What version of Codex CLI is running?

@openai/codex@0.105.0

What subscription do you have?

Plus

Which model were you using?

gpt5.2-codex but it didnt work at all

What platform is your computer?

Windows 11

What terminal emulator and version are you using (if applicable)?

#### Environment - OS: Windows 11 - Shell: PowerShell - Node: v24.12.0 - npm: 11.7.0 - Codex CLI: @openai/codex@0.105.0

What issue are you seeing?

#### Summary

codex fails to launch on Windows 11 with a fatal hardware capability check error.

#### Error

Fatal Error: HW capability found: 0x178BFBFF 0xBED8320B, but HW capability requested: 0x20000000 0x00.

#### Actual Behavior

Process exits immediately with the fatal hardware capability error above.

What steps can reproduce the bug?

#### Steps To Reproduce

  1. Install Codex globally:

npm install -g @openai/codex@0.105.0

  1. Run:

codex --version

What is the expected behavior?

Codex starts in terminal wrapper

Additional information

  • @openai/codex@0.104.0 works on the same machine:

codex-cli 0.104.0

  • This suggests a regression in 0.105.0 related to CPU feature requirements.

#### My Workaround

Downgrade to:

npm install -g @openai/codex@0.104.0

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