Nano11 Builder: How to Create a Lightweight Windows 11 ISO

If you’ve ever wished for a super-lightweight version of Windows 11 for testing or virtual machines, you’ll love what Nano11 Builder can do. This experimental PowerShell script takes a full Windows 11 ISO and strips it down—removing built-in apps, services, drivers, and core features—to produce a tiny, streamlined ISO often just 2.3–2.5 GB in size.

It’s not intended for daily use, since critical components like Windows Update, Microsoft Defender, BitLocker, audio services, and even Edge are removed. Instead, it’s perfect for disposable installs, labs, and VMs where you want the bare minimum Windows environment with maximum performance.

Here’s a step-by-step guide to using Nano11 Builder to create your own minimal Windows 11 ISO.

What You Need Before Starting

Before diving in, understand that the resulting ISO will be non-serviceable. You won’t be able to restore Windows Update, add features, or reinstall Microsoft apps later. Use it only in isolated test scenarios or virtual machines.

To get started, you’ll need:

• A Windows 11 ISO for x64 devices. See How to Download Windows 11 ISO Files (2025 Official Guide)
• The Nano11 Builder script from GitHub.
• A Windows PC with admin rights and enough free disk space for mounting and modifying the ISO.
• Recommended: en-US x64 media (other languages/architectures may need adjustments).

Step 1 — Download the Windows 11 ISO

1- Go to Microsoft’s Windows 11 download page.

2- Scroll to “Download Windows 11 Disk Image (ISO) for x64 devices.”

3- Choose your edition, confirm your language, and hit Download.

4- Save the ISO locally and note its path—you’ll mount it soon.

Step 2 — Get the Nano11 Builder Script

1- Visit the Nano11 GitHub repo.

2- Click Code → Download ZIP.

3- Extract the ZIP (e.g., nano11-main.zip) into a working folder, such as C:\Tools\nano11\.

Step 3 — Build Your Slim Windows 11 ISO

1- Mount the ISO: Right-click the Windows 11 ISO → Mount. Note the assigned drive letter (e.g., D:).

2- Open PowerShell as Administrator.

3- Set temporary execution policy (safe session only): Set-ExecutionPolicy Bypass -Scope Process

4- Run the script from its folder (adjust path as needed): & "C:\Tools\nano11\nano11builder.ps1"

5- When prompted, type R to run and Y to confirm.

6- Enter the drive letter of the mounted ISO (e.g., D).

6- Select the Windows edition index (usually 1 = Home, 6 = Pro).

8- Wait while the script trims the image and builds your nano11.iso using DISM and oscdimg.

9- If you changed execution policy permanently, reset it: Set-ExecutionPolicy Restricted

✅ Output:

• nano11.iso → your new minimal Windows 11 build.
• nano11.log → log file with process details.
• Final size: typically 2.2–2.5 GB.

Step 4 — Install Nano11 (Optional)

You can now:

• Use tools like Rufus to create a bootable USB from nano11.iso.
• Install in a VM or on non-critical hardware.

Expect a stripped-down Windows environment with no updates, no Defender, and many services disabled.

What Nano11 Removes

Here’s what you lose in exchange for a smaller, faster OS:

• Windows Update & WinSxS (no updates or added features).
• Microsoft Defender & security stack.
• Services: audio, search, BitLocker, biometrics, accessibility.
• Apps: Clipchamp, Xbox, Solitaire, Office Hub, News, Weather, etc.
• Drivers: non-essential ones removed (basic storage/networking remain).
• Browsers/cloud tools: Edge, OneDrive, legacy IE.

Compatibility & Notes

• Works with multiple Windows 11 editions (Home, Pro, LTSC).
• Best results with en-US x64 ISOs.
• Tested on Windows 11 25H2, 24H2, and earlier builds.
• Resulting install footprint: ~2.8–3.2 GB.

Troubleshooting Tips

• No “Mount” option on ISO? Right-click → Open With → Windows Explorer.
• Execution policy errors? Use: Set-ExecutionPolicy Bypass -Scope Process
• Confused by edition index? Script lists them—check carefully.
• Resulting size varies depending on edition, drivers, and compression.

How Nano11 Works (Technical Context)

Nano11 uses DISM to aggressively strip components from a mounted Windows image, then rebuilds a bootable ISO with oscdimg. An unattended setup file is included to skip Microsoft account setup and enable compact installation, further reducing footprint.

Why It Matters

For developers, testers, and enthusiasts, Nano11 Builder is a fast way to create disposable Windows 11 environments without the bloat. Instead of wasting resources on unused features and apps, you get a minimal OS perfect for VMs, test labs, and sandboxing experiments.

Conclusion

Nano11 Builder is not for everyday users—it’s for those who want to push Windows 11 to its bare minimum. By cutting away updates, Defender, apps, and drivers, you get a tiny ISO that installs lightning fast and runs lean.

If you’re working with test environments, VMs, or lightweight deployments, Nano11 Builder offers a fascinating look at how far Windows 11 can be slimmed down. Just remember: this build is non-serviceable—use it only where stability and updates aren’t required.