[BUG] VSCode opens multiple new windows when running `claude` command or during chat interactions on Windows

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Description

When running the claude command from the terminal or sometimes during chat interactions, VSCode opens multiple new windows instead of using the existing window. This creates a disruptive workflow with numerous VSCode instances accumulating over time.

Environment

• OS: Windows 11(24H2, 26100.4946)
• VSCode Version: 1.104.0
• Claude Code Version: 1.0.115
• Installation Method: npm

Attempted Solutions

1. Reinstalled Claude Code VSCode extension
2. Reinstalled Claude npm package
3. Killed all VSCode processes and restarted
4. Modified VSCode settings:

"window.restoreWindows": "none",
"files.hotExit": "off",
"window.newWindowDimensions": "default",
"window.openFoldersInNewWindow": "off"

Screenshot

<img width="1623" height="914" alt="Image" src="https://github.com/user-attachments/assets/1460e880-be63-4947-ab93-7af2af1ed762" />

!Image

What Should Happen?

Claude Code should use the existing window and do not open new VSCode window.

Steps to Reproduce

1. Open VSCode Terminal (PowerShell)
2. Run claude command
3. Multiple VSCode windows open simultaneously
4. Sometimes additional windows open during chat interactions

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.0.115

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell