Windows elevated sandbox setup fails with SetNamedSecurityInfoW error 5

Problem

Windows elevated sandbox setup repeatedly fails after I approve the UAC administrator prompt.

Environment

• Windows 11
• ChatGPT desktop app installed and updated through Microsoft Store
• Full access is disabled
• Requested sandbox mode: elevated

Steps to reproduce

1. Open the ChatGPT desktop app.
2. Select Work mode.
3. Click “Finish Windows setup” or “Try Windows setup again.”
4. Approve the Windows UAC administrator prompt.
5. Wait for the setup process to finish.

Actual result

The setup fails and the app displays:

Windows setup didn't finish

The diagnostic files report:

• helper_unknown_error
• read ACL run had errors
• SetNamedSecurityInfoW failed: 5

Windows error 5 indicates that the ACL operation was denied.

Expected result

The Windows setup should complete successfully and enable the elevated sandbox while retaining ChatGPT’s approval and sandbox protections.

Troubleshooting already completed

• Updated ChatGPT through Microsoft Store.
• Checked for Microsoft Store updates.
• Repaired the ChatGPT app through Windows Settings.
• Reset the app.
• Uninstalled and reinstalled the app.
• Restarted Windows.
• Repeated the setup and approved the UAC prompt.

The problem still occurs.

Feedback ID

no-active-thread-01a01576-5d58-7511-b69e-27707ef7435b

The relevant session logs were submitted through the in-app feedback mechanism.