Windows setup fails with helper_failed; Computer Use reports native computer APIs disabled

Windows setup in the ChatGPT desktop app fails with helper_failed. The Windows UAC administrator prompt does not appear.

Computer Use cannot open Windows Calculator. The agent stops with this message:

Native computer APIs are disabled.

This also happens when starting through Plugins → Computer Use → Try now, with @Computer explicitly selected. The requested task was to open Windows Calculator and calculate 2 + 2 without PowerShell or scripts.

Verified in the app:

Computer Use plugin is installed and enabled.

The Computer Use skill is enabled.

“Every app” is enabled in Computer Use settings.

Standard permissions are enabled; full access is disabled.

Computer Use plugin version: 26.908.40834. This is the plugin version, not a verified desktop app version.

The sandbox log was not found at %USERPROFILE%.codex.sandbox\sandbox.log after checking the expanded Windows path.

An in-app feedback report has already been submitted.

Feedback ID: 01a09a06-2195-7e10-912f-bb67046aa686

Please investigate why native Windows computer APIs remain disabled and how to complete Windows setup.

Start by reproducing the Windows setup failure and the Computer Use attempt to open Calculator, then check whether %USERPROFILE%.codex.sandbox\sandbox.log is created. Trace the setup and native API availability paths implicated by the helper_failed message and missing UAC prompt; done means setup completes, the prompt appears when expected, and Calculator opens without scripts.