[Windows Desktop] Computer Use fails to launch because child processes return spawn EPERM

Title:

[Windows Desktop] Computer Use fails to launch because child processes return spawn EPERM

Environment:

• ChatGPT/Codex Windows desktop app: 26.730.8199.0
• Computer Use plugin: 26.730.61639
• Platform: Microsoft Windows NT 10.0.26200 x64, version 25H2, build 26200.8875
• Uploaded thread / Session ID: 019fd74d-9b61-7a70-935e-6a2aed1d43db
• Model: 5.6 sol max

Issue description:

Computer Use is enabled, but it cannot initialize or inspect any Windows application. The failure occurs before there is any mouse movement, window enumeration, or interaction with the target application.

The original task was to inspect an already open Microsoft Excel workbook and report the workbook name, active worksheet, selected cell, and the locations of three cells containing test values. No modification was requested.

Computer Use never reached Excel. The built-in Computer Use example also failed with a launch-permission error.

Steps to reproduce:

1. Open Microsoft Excel and keep a workbook active.
2. Enable the Computer Use plugin.
3. Enable both “Any app” and “Microsoft Excel” under Computer Control settings.
4. Ask Computer Use to report the active workbook, active worksheet, and selected cell.
5. Observe that Computer Use fails before the cursor moves or any application window is discovered.

Diagnostic results:

• sky.list_apps() returns spawn EPERM.
• sky.list_windows() returns spawn EPERM.
• Node spawnSync("C:\\Windows\\System32\\where.exe", ["cmd.exe"]) returns EPERM.
• Attempting to spawn the bundled Node executable itself also returns EPERM.

This indicates that Node starts successfully, but the Windows sandbox prevents the Computer Use helper from spawning a required child process.

Expected behavior:

Computer Use should start its Windows control helper, enumerate open application windows, and inspect the active Excel session after receiving the required permission.

Actual behavior:

The helper fails during launch. No mouse movement occurs, no windows are discovered, and Excel is never accessed.

Troubleshooting already attempted:

• Confirmed that Computer Use is installed and enabled.
• Confirmed that “Any app” and “Microsoft Excel” access are enabled.
• Closed and reopened Excel.
• Restarted the ChatGPT/Codex desktop application.
• Restarted Windows.
• Used Windows Settings → Apps → ChatGPT → Repair.
• Tested the unelevated Windows sandbox setting.
• Tested with sandbox_private_desktop = false.
• The same spawn EPERM failure remained.

Possibly related to #21470, but this report reproduces the problem specifically with Computer Use on desktop app version 26.730.8199.0.

<img width="1431" height="861" alt="Image" src="https://github.com/user-attachments/assets/90ee50a1-b78e-40e8-95b8-ea179c1f89cb" />

<img width="1752" height="1452" alt="Image" src="https://github.com/user-attachments/assets/f33e51c1-feed-4f42-a919-dddd1f6e2982" />

<img width="1692" height="1043" alt="Image" src="https://github.com/user-attachments/assets/d5e1f6a6-1d0a-4ecd-b478-2cdb3e9526ba" />