System Informer
A free Windows tool for watching system resources, finding what locks files, and checking suspicious programs.
- Stars
- 16.4k
- Forks
- 1.8k
- Licence
- MIT
- Language
- C
- Last update
- 4 days ago
- Type
- App
What it is
System Informer is a free, open-source Windows utility that shows what is running on your computer. It lets you see which processes use the CPU, memory, disk and network, and which programs are using a file you cannot delete. People use it to track down runaway programs, debug software, and investigate possible malware.
- Find out which process is holding a file you cannot delete
- See which programs have active network connections and close them if needed
- Track real-time disk access and spot resource-heavy processes
- View stack traces, including kernel-mode, WOW64 and .NET support
- Create, edit and control Windows services
Great for
- Windows users who want more detail than Task Manager provides
- People trying to find which program is locking a file
- Developers profiling or debugging software on Windows
- Anyone who wants a portable tool that needs no installation
Not ideal for
- macOS or Linux users, since the README only lists Windows 10 or higher
- People who want a simple one-click cleaner, because this is a detailed monitoring tool that expects some technical knowledge
- Users who need a guaranteed malware scanner; the README describes it as a tool to help detect malware, not a complete antivirus
How to get it
- 1
Download the app
You'll need: Windows 10 or higher
Clone the repository to build from source
git clone https://github.com/winsiderss/systeminformer - 2
Run it
- Download the setup executable or the zip from the latest release on the project's downloads page or GitHub releases
- Install it, or extract the zip and run SystemInformer.exe if you want the portable version
- Open the Processes view to see what is running
- Use the search or highlighting features to find resource-heavy processes
- 3
Get the most out of it
- Use the file-usage feature to discover which processes are using a file you cannot edit or delete
- Use the network view to see active connections and close them if necessary
- Save settings on a USB drive by creating SystemInformer.exe.settings.xml next to the executable, as described in the README
- Use the stack trace view with kernel-mode, WOW64 and .NET support when debugging
Downloads
Strengths
- Free and MIT-licensed, with source code available on GitHub
- Small and portable, with no installation required according to the README
- Covers many areas (processes, files, network, disk, services) in one tool
Trade-offs
- Its power and detail can overwhelm beginners
- The README lists only Windows 10 or higher, and building it requires Visual Studio 2022 or later
- The README's build section is brief, so building from source may take extra effort
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| systeminformer (this) | 16.4k | App | intermediate | 4 days ago | Windows users who want more detail than Task Manager provides |
| RemoveWindowsAI | 13.6k | Dev tool | beginner | 8 days ago | Windows 11 users who want Copilot and Recall removed |
| locust | 28.3k | App | intermediate | 4 days ago | Backend or QA engineers who want load tests kept in version control as normal code |
| chezmoi | 22.1k | Dev tool | intermediate | 4 days ago | People who use more than one computer and want their settings to match |
| nginx-admins-handbook | 14.3k | Learning resource | beginner | 2.0 years ago | System administrators who already run NGINX and want practical tips |
| Betterfox | 11k | Other | beginner | 2 months ago | Firefox users who want privacy-focused defaults without installing extra software |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.