[Windows] Computer Use screenshots fail with 0x80070424 under CodexSandboxOffline; launch_app times out

Summary

On the current Windows desktop release, Computer Use can enumerate and activate existing windows and can send keyboard input, but it cannot capture screenshots or launch closed applications.

The Windows helper is spawned as CodexSandboxOffline. Windows has no CaptureService_* instance for that technical account, so Windows.Graphics.Capture fails even when the interactive user's capture service is running.

Environment

• Windows 11 x64, system component build 10.0.26100.8875
• ChatGPT/Codex Windows package: 26.803.5235.0
• Bundled Computer Use plugin: 26.803.41515
• Bundled @oai/sky: 0.6.2
• Computer Use target: windows
• Windows sandbox: elevated
• sandbox_private_desktop = false
• Computer Use setting Any App enabled

Microsoft Store reported no newer application package.

Screenshot reproduction

1. Open Snipping Tool manually.
2. Start a fresh node_repl session and import sky from @oai/sky.
3. Call list_windows() and select the returned Snipping Tool window.
4. Call activate_window({ window }).
5. Call get_window_state({ window, include_screenshot: true, include_text: true }).

Observed:

IGraphicsCaptureItemInterop.CreateForMonitor failed: The specified service does not exist as an installed service. (0x80070424)

list_windows() and activate_window() both succeed before the capture error.

Application launch reproduction

From a fresh Computer Use session:

await sky.launch_app({ app: "notepad.exe" });

Observed:

accessibility window-opened handler did not become ready

The same failure occurs with Calculator and with the full installed path to SnippingTool.exe. No target window is created.

Process and service evidence

The process ownership and session were inspected immediately after reproducing the capture error:

node_repl.exe             owner=<interactive user>       session=1
node.exe                  owner=CodexSandboxOffline      session=1
codex-computer-use.exe    owner=CodexSandboxOffline      session=1

Windows contained only the interactive user's capture-service instance:

CaptureService_c99b8    Running    Manual

There was no second CaptureService_* instance for CodexSandboxOffline.

Starting CaptureService_c99b8 through an elevated UAC-approved task succeeded, but a fresh Computer Use helper still returned the same 0x80070424 error. This indicates that the helper requires a per-user service instance for its own sandbox identity.

Checks and attempted remediations

• Verified that CaptureService template exists and is set to demand start.
• Verified C:\Windows\System32\CaptureService.dll exists and has a valid Microsoft signature.
• Re-registered Microsoft.ScreenSketch successfully; package status remains Ok.
• Enabled ChatGPT Computer Use Any App permission.
• Temporarily tested the documented Windows LetAppsAccessGraphicsCaptureProgrammatic = Force Allow device policy; it did not change the error and was fully reverted.
• Manually started the interactive user's CaptureService_*; it did not change the error.
• Removed verified stale Computer Use helper processes and repeated the test in a fresh session; no change.
• windows.sandbox = "unelevated" makes the Node kernel run as the interactive user, but the bundled runtime then cannot spawn the helper (spawn EPERM).
• sandbox_private_desktop = true fails to enumerate/control the real interactive desktop; compatibility desktop mode is required.
• The Windows implementation in this package directly spawns codex-computer-use.exe. The bundled native-pipe transport is present only under the macOS target.

Additional plugin/runtime mismatch

The installed Computer Use skill requires:

await sky.documentation("guidance")

but the installed @oai/sky object does not expose a documentation function. Its exported runtime surface contains the control methods but no documentation method.

Expected behavior

• The Windows Computer Use helper should run in a context that can use Windows.Graphics.Capture, or the app should broker capture through a process associated with the interactive user.
• launch_app() should reliably observe and return after the new window is ready.
• The bundled skill and @oai/sky runtime should expose matching APIs.

Actual impact

Working:

• list installed/recent apps
• enumerate existing windows
• activate an existing window
• keyboard input and key chords in an existing window

Not working:

• screenshots / visual inspection
• safe coordinate-based clicking based on a captured image
• launching closed applications
• documentation API required by the bundled skill

There is no supported local workaround that restores full Computer Use while preserving the Windows sandbox.