Installation FAQ

Common questions and troubleshooting for AtlasOS installation.

What do I need before installing?

  • Windows 11: Pro, Pro for Workstations, or Enterprise (Home is not supported; you can upgrade via product key if needed)
  • 64-bit CPU (x64) or ARM CPU (ARM64): Use the matching Windows ISO for your architecture (how to check)
  • A backup of all important data: Atlas installs by reinstalling Windows; your current setup will be replaced
  • USB drive: Only needed for the ISO injection method. The Playbook method (recommended) installs directly from Windows with no USB required

For a full checklist, see Installation requirements.

Who is Atlas designed for?

Atlas is for enthusiasts who want better privacy, performance, and control over Windows. We don’t recommend installing if:

  • You don’t fully own the computer
  • You’re not comfortable troubleshooting Windows issues
  • You’re not willing to reinstall Windows to remove Atlas

Can I install on a virtual machine?

Yes. Use the Playbook method. Some optimizations may not apply in a VM, but it works for testing.

Where is the Atlas ISO file?

Atlas doesn’t distribute a modified ISO. You use a stock Windows ISO and AME Beta to install Atlas. See Where is the Atlas ISO file? for details.

How long does installation take?

About 30-45 minutes, depending on your hardware and internet speed.

What if I get a BitLocker error?

If you see “Make sure BitLocker Drive Encryption is suspended”:

  1. Boot back into your original Windows
  2. Control Panel BitLocker Drive Encryption
  3. Click Suspend protection for your system drive
  4. Restart and continue installation

Tip

The drive stays encrypted; you can resume BitLocker after installation.

What if Windows Update fails?

  1. Check your internet connection
  2. Run Windows Update Troubleshooter (Settings System Troubleshoot)
  3. Restart and try again

What was removed from Windows?

Atlas disables many components for performance and privacy. See the Atlas source code for exact changes. Key removals:

  • Smart App Control - Permanently disabled (requires reinstall to restore)
  • Telemetry - Toggleable in Atlas folder
  • Microsoft account syncing, ads, tips - Disabled
  • Apps uninstalled by default: OneDrive (if not set up), Edge (optional), Steps Recorder, modern Media Player/Films & TV, and various Store apps (Mail, Weather, News, etc.). Most can be reinstalled from the Microsoft Store.

Why disconnect internet during Windows installation?

Disconnecting prevents Windows from auto-installing drivers and updates, giving you more control over the process.

What if installation fails?

Common causes:

  • Not enough disk space (need at least 64GB free)
  • Corrupted ISO file (re-download)
  • BitLocker enabled (suspend it first)
  • Hardware incompatibility (check Windows 11 requirements)

How do I remove Windows.old?

  1. Settings System Storage
  2. Click Temporary files
  3. Select Previous version of Windows Remove files

Tip

This frees up significant disk space after you’ve retrieved any needed data.

What should I do after installation?

After installation, follow these guides:

How do I uninstall AtlasOS?

Atlas requires a full Windows reinstall to uninstall. See our Reverting Atlas guide for step-by-step instructions.