System Informer

System Informer is a free, MIT-licensed system monitor for Windows 10 and later, in 32-bit and 64-bit builds. It presents a detailed, color-highlighted view of running processes along with graphs and statistics, which helps administrators and developers find programs that consume excessive resources or run out of control. Written in C, it is the project formerly known as Process Hacker and is maintained by Winsider Seminars & Solutions.

The tool goes deeper than the built-in Task Manager. It can show which processes hold a file open when you cannot edit or delete it, list programs with active network connections and close them, and report disk access in real time. For debugging it displays detailed stack traces with support for kernel mode, WOW64, and .NET, and it can create, edit, and control Windows services beyond what the standard services console offers.

System Informer is small and portable and needs no installation. It can keep its settings next to the executable, which suits running it from a USB drive. The source code is on GitHub and builds with Visual Studio 2022 or later, and bugs and feature requests go through the GitHub issue tracker. Because it can reveal and manipulate processes, security analysts also use it when looking for suspicious activity.