Windows Desktop: "Finish Windows setup" never completes, preventing sandboxed edits

Environment
App: ChatGPT Codex Desktop (Microsoft Store)
Version: 26.707.3748.0
OS: Windows 11 Pro
Subscription: ChatGPT Plus
Summary

The initial "Finish Windows setup" never completes.

Because of that, Codex cannot perform sandboxed file edits.

The runtime downloads successfully and the sandbox runtime appears to install correctly, but every editing attempt fails before modifying files.

Reproduction
Install ChatGPT Codex from the Microsoft Store.
Launch the application.
Click Finish Windows setup.
The app immediately returns:
Windows setup didn't finish

The setup never completes.

Expected behavior

Finish Windows setup should complete successfully.

Codex should be able to edit files inside a trusted local workspace.

Actual behavior

The setup loop never completes.

Even after the runtime is downloaded, every file-edit attempt fails because the sandbox helper cannot initialize.

What I verified

I spent considerable time narrowing this down.

Verified:

Runtime downloads successfully.
Runtime directory is fully populated.
node.exe exists.
codex-computer-use.exe exists.
config.toml is valid.
Playwright MCP works.
Workspace is trusted.
Runtime directories can be renamed normally.
Rebooted multiple times.
Deleted runtime and allowed it to rebuild.
Disabled Webroot realtime protection.
Tried both
[windows]
sandbox = "elevated"

and

[windows]
sandbox = "unelevated"

with identical results.

Windows Event Viewer

Application log contains no Codex crash or .NET runtime failure during setup.

AppModel-Runtime/Admin shows successful Desktop AppX container creation and deletion.

No AppContainer errors are recorded.

Additional observations

Earlier Codex logs also reported:

thread-store internal error

failed to read session metadata

rollout jsonl is empty

I do not know whether that is related, but it may help diagnose the problem.

I have complete PowerShell output from Event Viewer and Codex diagnostics if the team would like me to attach them.