uSimmics (formerly QucsStudio) is a free, open-source circuit simulator developed as a non-commercial project led by Michael Margraf. It originated as a fork of the Qucs (Quite Universal Circuit Simulator) project and has been rebranded as uSimmics as of 2026.
This article covers the installation procedure for users who are working with versions released under the legacy QucsStudio name, or who require an older build for compatibility reasons.
What You Will Learn
- System requirements for uSimmics (formerly QucsStudio)
- How to download the correct package from the official website
- How to extract and launch the application without an installer
- How to customize the working directory (project storage location)
- Notes on the UI language and interface settings
Prerequisites
System Requirements
uSimmics (formerly QucsStudio) supports Windows® operating systems only. If you are on macOS or Linux, you will need to run Windows inside a virtual machine (e.g., VirtualBox or Parallels) before proceeding.
Installation Steps
1. Download from the Official Website
Visit the official uSimmics (formerly QucsStudio) website and download the latest zip archive.
Example filename:
QucsStudio-X.X.X.zip
2. Extract the ZIP Archive
Extract the downloaded zip file to any directory of your choice. No installer is required — the application runs directly from the extracted folder.
3. Launch the Executable
Inside the extracted folder, navigate to the bin subdirectory and double-click qucs.exe to start uSimmics (formerly QucsStudio).
extracted-folder/
└── bin/
└── qucs.exe ← double-click this file
Launch Options and Working Directory Configuration
Default Working Directory
On first launch, uSimmics (formerly QucsStudio) automatically creates a .qucs folder in your user home directory and uses it as the working directory. All project files and configuration data are stored there.
Customizing the Working Directory
You can specify a custom working directory by passing a path as a command-line argument at launch:
qucs.exe -"C:\users\guest\projects"
To make this setting permanent, edit the start.bat file included in the extracted folder so that the argument is applied every time the application starts.
UI Language
uSimmics (formerly QucsStudio) currently provides an English-only interface. There is no official localization for other languages. All menus, dialogs, and documentation are displayed in English.
If you are unfamiliar with specific menu terms or simulation concepts encountered in the interface, the articles on this blog (denki-sim.blog) include explanations of key terminology and step-by-step walkthroughs.
A Message from the Developer
From Michael Margraf (translated):
uSimmics (formerly QucsStudio) is a non-commercial project developed entirely in private time. Bug reports, test results, and documentation contributions are always welcome. Supporting other users on the forum is also greatly appreciated. If you find this software useful, please consider making a donation.
Related Articles
- uSimmics (formerly QucsStudio) Overview and Getting Started
- uSimmics (formerly QucsStudio) Initial Configuration Guide: Optimizing Your Simulation Workflow [2026]
- uSimmics (formerly QucsStudio) Circuit Editor Basic Operations Guide [2026]
- DC Analysis with uSimmics (formerly QucsStudio) [2026]
- How to Change the Project Folder Location in uSimmics (formerly QucsStudio)
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