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Codex Issues / #35965

Windows app: "Finish Windows setup" never starts elevated sandbox setup; `sandbox = "unelevated"` works

Open 💬 4 comments Opened Jul 29, 2026 by kateriez
💡 Likely answer: A maintainer (github-actions[bot], contributor) responded on this thread — see the highlighted reply below.

Environment

  • Windows 11
  • ChatGPT MSIX package OpenAI.Codex
  • Version: 26.721.11231.0

Problem

On first launch the app displays Finish Windows setup. Clicking Try Windows setup again immediately returns to the same screen.

Unlike other reports, the elevated sandbox setup helper never appears to start.

Expected

The app launches the elevated sandbox setup helper, requests elevation if needed, completes setup, and starts normally.

Actual

  • No UAC prompt.
  • codex-windows-sandbox-setup.exe is never launched.
  • No sandbox log is created under %USERPROFILE%\.codex.
  • The app repeatedly asks to finish Windows setup.

Diagnostics

  • UAC confirmed working (elevated Command Prompt prompts normally).
  • Reinstalled ChatGPT.
  • Get-AppxPackage OpenAI.Codex reports Status = Ok.
  • codex-windows-sandbox-setup.exe and elevation_service.exe exist in the package.
  • No Application Error or Windows Error Reporting events generated.
  • WMI process tracing shows no launch of the sandbox setup helper after clicking Try Windows setup again.

Workaround

Creating %USERPROFILE%\.codex\config.toml with:

[windows]
sandbox = "unelevated"

allows the application to start and function normally.

This seems distinct from reports where the helper runs but setup loops, since in this case the helper never starts.

View original on GitHub ↗

4 Comments

github-actions[bot] contributor · 29 days ago

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

  • #34748

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kateriez · 29 days ago

This appears related to #34748, but the failure occurs at a different stage.

In my case, no UAC prompt appears and WMI process tracing confirms that codex-windows-sandbox-setup.exe is never launched. No sandbox log is created. Setting sandbox = "unelevated" immediately allows the app to work.

In #34748, the setup helper ran and UAC was approved, so this may be a distinct failure mode rather than a duplicate.

egedensondakika35-maker · 21 days ago

I can confirm this issue.

Environment

  • Windows 11 Pro 25H2
  • OS Build 26200.8875
  • ChatGPT Microsoft Store version
  • OpenAI.Codex 26.730.8199.0

Behavior

Unlike the original report, I do receive the Windows UAC prompt.

However, after clicking "Yes", absolutely nothing happens.

The application immediately returns to:

"Windows setup incomplete"

and remains stuck in the "Finish Windows setup" loop forever.

Already tested

  • Reinstalled from Microsoft Store
  • Reset-AppxPackage
  • Package Status = OK
  • WebView2 installed
  • Windows App Runtime installed
  • ClipSVC running
  • AppXSvc running
  • Administrator account
  • Reset local Codex state

None of these steps changed the behavior.

Task Manager shows multiple Codex processes running while setup never completes.

egedensondakika35-maker · 21 days ago

Additional diagnostics:

  • WebView2 Runtime version: 151.0.4129.59
  • ClipSVC service is running.
  • AppXSvc service is running.
  • Get-AppxPackage Status = OK.
  • The package installs successfully from Microsoft Store.
  • Task Manager shows multiple Codex processes while the setup never completes.
  • Windows Error Reporting (WER) generated reports for OpenAI.Codex during setup attempts.

This appears to be related to the elevated sandbox setup never completing rather than a corrupted installation.