Windows Monitor Manager Service

中文文档 | English

A powerful Windows Service application written in Rust that provides a RESTful API and Web UI to manage physical monitors and display topology remotely.

It is designed to work robustly even in Session 0 (Windows Service) and at the Login Screen (WinLogon), solving common issues where display APIs fail when no user is logged in.

✨ Features

• Session 0 Isolation Bypass: Uses advanced token stealing and process snapshotting (similar to RustDesk) to inject an agent into the active console session (User Desktop or Login Screen).
• Works at Login Screen: Can enumerate and switch displays even when no user is logged in.
• Web UI: Embedded modern Web UI for easy management from any device (phone/laptop).
• Single Binary: All components (Service, API, Agent) are packed into a single executable monitor-service.exe.
• Robust Display Control: Uses Windows CCD (Connecting and Configuring Displays) API instead of legacy GDI for reliable monitor identification and topology switching.
• Smart Filtering: Automatically hides phantom "Generic Non-PnP Monitors" and inactive displays.
• Exclusive Activation: Supports "Show Only on X" mode by strictly disabling all other display paths.

🚀 Quick Start

1. Console Mode (Testing)

Run directly in a terminal to test functionality without installing as a service.

.\monitor-service.exe --addr 0.0.0.0:3000

Then open http://localhost:3000 in your browser.

2. Install as Windows Service

To have it run automatically at boot (and work at the login screen):

1. Open PowerShell as Administrator.
2. Create the service (Replace path with your actual path):

   sc.exe create MonitorService binPath= "C:\path\to\monitor-service.exe --service --addr 0.0.0.0:3000" start= auto

   Note: The space after binPath= is required.

3. Start the service:

   sc.exe start MonitorService

3. Stop/Uninstall

sc.exe stop MonitorService
sc.exe delete MonitorService

🛠️ Usage

Web Interface

Visit http://YOUR_PC_IP:3000 to:

• View list of active physical monitors.
• Click a monitor card to activate ONLY that monitor.
• Use quick actions: Internal (PC Screen), External (Second Screen), Extend, Duplicate.

Command Line Arguments

Usage: monitor-service.exe [OPTIONS] [COMMAND]

Options:
  --service             Run as a Windows Service
  --addr <ADDR>         IP address and port to listen on [default: 0.0.0.0:3000]
  -h, --help            Print help

Commands:
  agent                 Run as Agent (Internal use for session injection)

🏗️ Build Instructions

Requirements: rustup, cargo.

1. Clone the repository.
2. Build for release:

   cargo build --release

3. The binary will be at target/release/monitor-service.exe.

🧩 Architecture

• Service Process (Session 0): Runs the Axum Web Server and handles API requests. It detects the active console session ID.
• Agent Process (User Session): The Service uses CreateProcessAsUserW to launch itself (monitor-service.exe agent) inside the active user session (or WinLogon session).
• Communication: The Service captures the stdout of the Agent process to get display lists and results.

⚠️ Troubleshooting

• "No monitors found": Ensure the service is running and you are not in a Remote Desktop (RDP) session (RDP uses a virtual display driver). This tool manages physical GPU outputs.
• Duplicate Monitors: The tool automatically filters duplicates based on hardware Target IDs. If you still see duplicates, they might be ghost entries from the driver; try restarting the PC.

Acknowledgements

• Thanks to RustDesk.