nano11: Ultra-Light Windows 11 ISO for Lab and VM Testing

NTDEV’s community ecosystem has produced yet another extreme take on Windows 11: nano11, a script-driven rebuilder that pares a stock Windows 11 image down to astonishingly small sizes — an ISO reportedly just over 2 GB and an installed footprint under 3 GB when combined with compression — by stripping large swathes of features, drivers, and servicing infrastructure to produce an ultra‑light test image for old PCs and lab use. (neowin.net) (github.com)

Background​

Windows 11’s growing feature set has produced a parallel ecosystem of community projects that rebuild or scrub the installation media to create minimal images. Projects such as Tiny11 and tiny11 core established the pattern: use official Microsoft ISOs and Microsoft tooling (DISM, image servicing flags) then remove optional packages, inbox apps, and driver stacks to make installs far smaller and faster to deploy. NTDEV’s Tiny11 family popularized this approach, showing that LZX/LZMS compression and careful package removal can reduce a stock installation that normally consumes tens of gigabytes down to a handful of gigabytes. (techspot.com) (neowin.net)
nano11 arrives in that lineage as a purpose‑built “superlite” variant maintained in a small community of builders and forks on GitHub and related pages. The nano11 project provides a builder script — a forked toolchain that automates image mounting, package removal, and ISO re-creation using only Microsoft utilities (DISM, oscdimg, etc.). The official nano11 project repositories and its post‑setup tooling document the project’s goals and what is removed or disabled by default. (github.com) (github.com)

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What nano11 actually does​

The stated goal​

nano11’s stated intent is simple: produce a tiny, testable Windows 11 image that keeps core boot and runtime capabilities while shedding everything nonessential to save space and speed up installations. The builder script works against an official Microsoft ISO, removes an extensive list of packages and components, and re‑packages the result as a bootable ISO. The project emphasizes using Microsoft-provided utilities only, minimizing reliance on third‑party binaries. (github.com)

Typical reductions​

Community reporting and the project’s materials say nano11 can:

• Reduce the base image size significantly — the repo and community posts describe final ISOs far smaller than stock. One reported result: an ISO “a little over 2 GB,” and an installed image around 2.8 GB when using aggressive compression. That figure is extraordinary compared with a stock Windows 11 install that often consumes ~20 GB or more. (neowin.net)
• Remove major inbox features such as Microsoft Edge, Windows Defender/Antimalware, some IME/language components, many optional drivers, wallpapers, and convenience apps.
• Disable or remove servicing components (notably Windows Update) in some variants, making the resulting build non‑serviceable via normal Windows Update flows. This is emphasized as intentional — nano11’s aim is to be a tiny testbed or lab image, not a daily‑driver replacement. (neowin.net)

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Under the hood — compression and image servicing​

Microsoft tooling: DISM and oscdimg​

nano11 follows the common pattern used by modern Windows image rebuilders: mount the original ISO's install.wim or install.esd, run DISM to remove packages, features, and drivers, and then re-export the image and create an ISO with oscdimg or the Windows ADK tooling. The builder’s README emphasizes the use of only Microsoft tools to avoid external dependencies — a design decision aimed at auditability and predictable builds. (github.com)

LZX / LZMS compression​

Two related but distinct technical moves yield compression wins:

• LZMS (also referred to in community writeups as LZX-style compression) is the on-disk compression used by Windows component stores and some packaging flows. Using the image export flags (/Compress:recovery or LZX/LZMS compression via DISM) can produce dramatically smaller install images at the cost of additional CPU time during export and potentially different servicing behavior.
• After the image is created, additional compression or filesystem tricks (NTFS compression, advanced CAB deltas, or the use of certain deployment flags) can make runtimes smaller on disk.

The reported numbers — ISO near 2 GB and installed size ~2.8 GB — depend on aggressive compression and removing many components that inflate the WinSxS store. Tech reporting on related projects such as Tiny11 documents similar use of LZX compression to get Windows 11 installs down to markedly smaller footprints. That said, exact compression gains vary by build, language pack, and what’s removed. (techspot.com)

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What is removed — and what you lose​

nano11 takes a maximalist approach to trimming. Removal lists vary between forks and releases, but common removals include:

• Windows Update / servicing components (in some builds), preventing normal online updates
• Windows Defender / built‑in antivirus
• Microsoft Edge and Copilot components
• Inbox apps: Mail, Calendar, Media Player, Clipchamp, Xbox apps, and many telemetry/consumer features
• Significant parts of WinSxS and optional language/IME packs
• Nonessential drivers and some driver packages that increase the component store

These removals buy size and speed, but they also bring important consequences:

• No normal updates: if Windows Update or servicing is removed or broken, you cannot apply Microsoft updates via the normal channels. This impacts security and supportability.
• Security surface: removing Defender or other protection layers means you must supply alternate antivirus and hardening tools.
• Compatibility risks: missing drivers or system components will break hardware or software that depends on them; e.g., Windows Hello, fingerprint or face authentication, some GPU features, and specific peripherals may be nonfunctional.
• OEM and feature dependencies: certain features (OneDrive integration, in-box Office elements, Cortana/Copilot) are intentionally removed; for users or environments that rely on these, the image is unsuitable.

Multiple community writeups warn that these images are intended for testing, virtualization, and experimental use, not for mission-critical or production endpoints. (neowin.net)

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Practical use cases​

nano11 and similar builds are useful in a few clear scenarios:

• VM testbeds and sandboxing: lightweight images are fast to spin up, occupy less disk, and speed iterative testing for drivers or installers.
• Resource-constrained hardware labs: old laptops or embedded devices used for testing where a full Windows install is impossible or impractical.
• Imaging exercises and forensic labs: teams that need reproducible minimal images for benchmarking or QA.
• Education and experimentation: enthusiasts learning about Windows servicing and DISM workflows.

They are explicitly not recommended for daily use with personal data, corporate endpoints, or systems that must remain patched and compliant. The trade-offs are simply too great for most production needs. (neowin.net)

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Security, servicing, and legal considerations​

Security and patching​

Removing Windows Update or Defender dramatically increases risk. A machine that cannot receive security updates is exposed to new vulnerabilities immediately after the image’s snapshot date. To mitigate:

• Consider using the image only in offline or segmented lab networks.
• If you must run networked workloads, install and maintain an alternative endpoint protection suite and a clear update strategy (manually reimaging with a patched ISO).
• Treat nano11 images as ephemeral: snapshot, test, tear down.

Integrity and supply chain​

Community builders generally repackage official Microsoft ISOs, but any time you run third‑party scripts or download prebuilt ISOs you must consider supply‑chain risk. Best practices:

• Build from an official Microsoft ISO you downloaded yourself.
• Inspect scripts — nano11 builders aim to use Microsoft utilities only; review their scripts before running them.
• Prefer open repositories with visible commits and active issue discussions over anonymous, unverified downloads. (github.com)

Licensing and activation​

These custom builds are not a separate license: they still require a valid Windows license for activation. Stripping features does not remove Microsoft’s licensing requirements. Community posts and project pages reiterate that activation with an appropriate key remains necessary. (neowin.net)

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How nano11 compares to Tiny11, Tiny11 Core, and AtlasOS​

• Tiny11 / tiny11 builder (NTDEV): mature, well‑known project focused on de‑bloating and optional removal of inbox apps. It introduced tiny11 core variants that went even smaller (2 GB ISO / ~3 GB install) but at the cost of updates and many features. Tiny11 has a larger following and more reporting, and its author documents LZX compression workflows that reduce installed size dramatically. (techspot.com)
• nano11: positioned as another project in the same space, with its own post‑setup toolkit and emphasis on Enterprise‑based sources (e.g., 24H2 LTSC roots in some community builds). It aims to be a superlite spin with post‑setup toolkits to manage Copilot/Edge toggles. nano11’s values are similar: small ISO, quick install, suitable for experiments. (github.com)
• AtlasOS: a different approach focused on performance tuning and disabling services, not necessarily creating a dramatically reduced on‑disk footprint. AtlasOS is more of a performance tuning profile than an ISO rewriter.

For most readers, Tiny11 is the best‑documented starting point; nano11 is an alternative with slightly different removal choices and tooling. Regardless, all follow the same core tradeoff: space and speed versus feature completeness and maintainability. (techspot.com)

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Building and testing nano11 — a practical outline​

The community builder scripts automate most of the heavy lifting. A conservative step-by-step approach for any WindowsForum user who wants to experiment:

• Back up any data and use a test machine or VM. Never test on a production device.
• Download an official Windows 11 ISO from Microsoft for the target build you intend to modify.
• Clone or download the nano11 builder repository (or tiny11maker if you prefer NTDEV’s work). Inspect the .bat and PowerShell scripts to ensure they do not call opaque or external executables you cannot audit. (github.com)
• Mount the ISO, run the builder script as documented, and select the SKU/language options the script supports.
• Create a bootable USB from the resulting ISO and deploy to a VM first.
• Test boot, device drivers, networking, Windows Update, and updateability. If Windows Update is removed, test your fallback update method.
• If the image is suitable for your lab use, document the build options and retain the scripts for reproducibility.

This conservative approach reduces risk and ensures you can recover if the image breaks hardware support or has inadvertent omissions.

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Strengths and promises​

• Space efficiency: For labs, VMs, and users with tiny SSDs, these builds offer huge disk savings.
• Fast installs: Smaller images and fewer packages yield quicker deployments.
• Control: Builders give power users fine‑grained choices about what stays in the OS.
• Reproducibility: Scripted pipelines enable repeatable images for QA and testing.

These are real, practical benefits for the right audience. Projects such as tiny11 have demonstrated that LZMS compression plus careful package removal can drop an install from ~20–30 GB to single-digit gigabytes in real environments. (techspot.com)

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Risks, caveats and red flags​

• Non‑serviceable images: If Windows Update or servicing components are removed, the OS cannot be kept secure via Microsoft’s channels.
• Driver and feature breakage: Removing broad driver sets and component store pieces will break features unpredictably — especially hardware authentication (Windows Hello), some display drivers, and OEM features.
• Supply chain and trust: Prebuilt ISOs from third parties are inherently riskier than building your own from an official ISO and audited scripts.
• Not for daily use: Community maintainers explicitly state these images are for tests and experiments, not as replacements for supported, updated installations. (neowin.net)

Any deployment should carefully weigh these risks against the benefits. For production systems or machines holding personal data, the recommended path remains: use Microsoft‑supported images and apply patches.

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What the community should watch for​

• Servicing behavior across Windows versions: Microsoft occasionally hardens or changes how features, inbox apps, and Store components are serviced. That drives a continual “whack‑a‑mole” for builders who try to prevent reinstallation of removed components. Tiny11’s recent updates explicitly added routines to block Copilot, Outlook and other persistent components; similar challenges will affect nano11 maintainers. (tomshardware.com)
• Compression compatibility: Compressed images and uncommon servicing states might behave differently in future Windows updates; test upgrade flows carefully.
• Community auditing: Because these projects operate on the boundary of official support, stronger community auditing and transparent changelogs are crucial to maintain trust.

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Bottom line for WindowsForum readers​

nano11 is another evolution in a community effort to answer a simple user pain point: Windows 11’s modern defaults are heavy, and hobbyist/IT communities want lean, fast, and testable images. The project delivers very small ISOs and installed footprints by aggressively removing packages and using Microsoft image tooling and compression, which makes it compelling for virtual labs and hardware‑constrained experiments. (github.com)
However, the practical reality is that these images sacrifice updateability, out‑of‑the‑box security, and hardware compatibility. The correct use case is narrow: lab and test environments where ephemeral, tiny images are valuable — not production machines or anywhere security and patching are required.

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Recommendation checklist before trying nano11​

• Back up everything; use VMs or expendable test devices.
• Build from an official Microsoft ISO you download yourself.
• Inspect all scripts before running; prefer builders that use only Microsoft utilities.
• Plan an update/patching strategy if you must run networked workloads.
• Use the image only for testing, driver validation, or constrained lab scenarios.

Community projects such as nano11 and Tiny11 show what is possible when you pair Microsoft’s image tooling with aggressive trimming and compression. They are powerful tools — but they must be matched to the right task and handled with awareness of the substantial trade‑offs they impose. (techspot.com)

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This article summarized the core claims about nano11’s approach, verified the existence of the builder and its goals, compared it to sibling projects in the Tiny11 family, and outlined the technical and practical trade‑offs readers should weigh before experimenting with super‑slim Windows 11 images. (github.com)

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Source: Neowin This script shrinks Windows 11 install down to less than 3GB of disk space