atlas-os/atlas

AtlasOS, or Atlas, is an open-source project that modifies Windows to improve performance, privacy, and usability. Rather than distributing a custom Windows disk image, Atlas works by using a tool called AME Wizard with a Playbook, a transparent, script-like configuration file, that applies a series of changes to an existing Windows installation. This approach makes the modifications easier to audit than traditional custom Windows ISOs. On the privacy side, Atlas removes the majority of telemetry embedded within Windows and applies group policies to minimize data collection. For performance, it implements changes to improve Windows responsiveness without breaking essential features, and explicitly avoids tweaks that only produce a placebo effect. On the usability side, it removes commonly unneeded applications (which remain reinstallable), adjusts interface settings, and disables advertisements. Atlas takes a different approach to security compared to many Windows modification projects: rather than stripping all security features by default, it lets users make informed choices. Optional features like Windows Defender, SmartScreen, Windows Update, User Account Control, and CPU mitigations can each be toggled with an explanation of the pros and cons of each setting. The project complies with Microsoft Windows Usage Terms because it does not redistribute a modified Windows ISO or alter Windows activation. The Atlas Playbook is licensed under GPLv3. Documentation and installation instructions are available at docs.atlasos.net.