System Ninja is a program for cleaning your computer of unwanted junk that constantly slows your entire system down. Apart from the useful file cleaner, the program also has a Startup Manager, Process Manager and P3P Registry History cleaning tool.

File Cleaner

System Ninja features a powerful cleaning application which scans your computer for files that can be deleted to save hard drive space and speed up your computer. Files and directories currently cleaned include:

  • Windows Temporary Files.
  • .tmp files, in all directories
  • Thumbs.db files, and other thumbnail caches.
  • Mac icon files, which are unsupported by Windows.
  • Game caches, increase the speed of your PC games. Currently supports only The Sims 2 & The Sims 3.
  • Windows Logs
  • Common Torrent Tags (Those annoying little .txt files that come with many torrents.)

Startup Manager

The integrated startup manager allows you to dictate what can and can't run when you turn on your computer. It supports Run, RunOnce and Sheduled Tasks files and registry keys. Removing startup items is a useful way of improving the speed of your computer.

History Eraser

The history eraser function allows you to quickly remove the browsing traces left over by Internet Explorer and Mozilla Firefox. Also supported is the P3P History which is stored within the Windows Registry and is usually missed by other cleaning applications, such as the popular CCleaner and Advanced System Care.

Process Manager

The process manager allows advanced users to quickly end unwanted programs without the hassle of running Task Manager. Whats more; process manager automatically highlights processes that are commonly associated with Viruses or Spyware. The Malicious Process feature can detect over 75 of the most common malicious processes.

Multiple Languages Supported

System Ninja is available in several languages, including Dutch, English, Portuguese, Spanish and French. If you want to help out by contributing a translation, please email me.

New process manager

More information is shown by the new Process Manager interface. RAM Consumption, Program Name and ProcessID are shown. The powerful process termination feature remains unchanged.

Implemented a scripting language and parser

This will allow me (and potentially other people) to add new cleaning rules and paths to System Ninja, without requiring them to be hard-coded into the program. "NinjaScript" (as I'm calling it) will also serve a number of under-the-hood purposes to make everything a bit simpler. If you would like to create your own System Ninja cleaning rules in NinjaScript, check out the documentation.

What's New

System Ninja 4.0 is now available. This release brings a redesigned user interface, full support for Windows 11, support for high resolution displays, plus countless bug fixes and usability improvements.

We released the beta of System Ninja 4.0 six months ago, and we're finally confident that all the worst bugs have been found and fixed. Thank you to the thousands of people who tested 4.0 and reported their findings.

What's new in System Ninja 4.0:

  • Brand new user interface design and color scheme.
  • Windows 11 compatibility.
  • Added Recycle Bin to the list of cleaning options.
  • Fixed issue where System Ninja would reset "Automatic Updates" options for Mozilla products.
  • System Ninja will now correctly detect the Windows version number on Windows 10 and 11.
  • System Ninja will now warn against certain dangerous or silly actions with the DuplicateFinder tool.
  • Added recommendations to many new startup items.
  • Added Danish Localization (props René Blumensaadt).
  • [Pro] Added some new UI templates to the Custom Branding module, including Office2016 and Metro.
  • "Common Torrent Tags" cleaning has been removed as a cleaning option. These files are now cleaned when "Temporary Files" is checked.

New changes since System Ninja 4.0 Beta:

  • Fixed high DPI scaling issues on the "drive selector" dialog and the Pro UI
  • Prevented System Ninja from deleting its own log files.
  • Fixed issue where System Ninja would remove Chrome and Edge extension settings
  • Fixed issue causing Pro scans to get stuck at 99%
  • Modified installer to check that .NET 4.8 is installed.
  • Too many UI tweaks to list.