Do not disable the sandbox.A display defect has two creation boundaries. Preserve policy while fixing each creator.

Route by the process that owns creation.

Local subprocesswindowsHide

Apply to Node spawn and taskkill teardown while preserving pipes and cancellation.

Windows ACL sandboxSTARTUPINFO

Combine STARTF_USESHOWWINDOW with SW_HIDE in both restricted-token spawn variants.

Not equivalentCREATE_NO_WINDOW

rc.8 records 0xC0000142 failures for restricted-token children.

Four probes reveal the owner.

PowerShell

Capture stdout and stderr.

Node or Git

Exclude a pwsh-only issue.

Sandbox

Exercise the restricted-token path.

Terminal host

Separate GUI-parent behavior.

-WindowStyle Hidden is not a general repair.

It is PowerShell-specific, can apply after creation, and cannot cover Node, Git, or the sandbox's process-creation contract.

A hidden window is only one gate.

Visibility

No flash at start or teardown.

I/O

stdin, stdout, stderr, and exit remain correct.

Control

Timeout, cancel, and tree kill still work.

Security

Sandbox allow and deny behavior is unchanged.

Primary evidence.

Keep the complete Windows runbook.

The canonical guide includes process-tree evidence, bounded operator options, unsafe shortcuts, two source repair contracts, eleven acceptance gates, and an incident record.

Read the complete runbook