[Bug]: Codex Install action in Windows onboarding fails with missing OSArchitecture property

Find the onboarding flow for Windows in the T3 Code repository, likely in a setup or agents directory. Look for the PowerShell command that triggers the Codex installer. The fix may involve updating the command or providing a fallback for PowerShell 5.1. Check the linked upstream issue to understand the OSArchitecture property problem. Test the workaround or alternative installation method to verify it resolves the onboarding failure.

Before submitting

• I searched existing T3 Code issues and did not find this exact onboarding failure.
• I included the command, error, and screenshot needed to investigate.

Area

Windows desktop onboarding / Codex provider setup

Steps to reproduce

1. Open T3 Code on Windows and go to the Agents step of setup.

2. With Codex shown as Not found, select Install.

3. Run the PowerShell command T3 Code presents:

   irm https://chatgpt.com/codex/install.ps1 | iex
   

Expected behavior

The recommended installation path installs Codex CLI, or T3 Code offers an actionable alternative when that installer cannot run in the user's PowerShell environment.

Actual behavior

The installer stops immediately with a missing OSArchitecture property error. This prevents completing the Codex provider setup through the command offered by T3 Code.

Impact

Codex cannot be set up through this onboarding path on the affected Windows machine.

Version or commit

T3 Code version not visible in the screenshot.

Environment

Windows. The Windows and PowerShell versions are not captured in the screenshot.

Logs or stack traces

iex : The property 'OSArchitecture' cannot be found on this object. Verify that the property exists. (English translation of the error shown in the screenshot.)
CategoryInfo          : NotSpecified: (:) [Invoke-Expression], PropertyNotFoundException
FullyQualifiedErrorId : PropertyNotFoundStrict,Microsoft.PowerShell.Commands.InvokeExpressionCommand

Screenshots, recordings, or supporting files

Related issue

The Codex CLI installer has an existing upstream report for the same OSArchitecture error on Windows PowerShell 5.1: https://github.com/openai/codex/issues/19559. This T3 Code report is about the setup path and guidance presented in its onboarding flow. The PowerShell version on this machine has not been confirmed.

Workaround

Not tested on this machine. A different Codex CLI installation method may bypass the PowerShell installer.