KMS38 Windows Activation Hack Shuts Down After November 2025 Update

Microsoft’s November Patch Tuesday has quietly closed off one of the most convenient — and widely abused — offline activation routes for Windows 10 and Windows 11, effectively neutering the long-running “KMS38” trick used by the Microsoft Activation Scripts (MAS / MASSGRAVE) project and forcing users who relied on the hack to confront unactivated systems or find alternative, often riskier workarounds.

Overview​

The change is narrow in scope but broad in consequence: Microsoft’s cumulative updates released on November 11, 2025 (most notably KB5068861 and the October preview content consolidated into it) include servicing and setup adjustments that remove or alter the legacy upgrade behaviors KMS38 depended on, meaning crafted “GenuineTicket” artifacts no longer persist or are no longer processed the way they once were. The MAS maintainers have acknowledged the shift and updated their codebase to remove KMS38 from active options — a tacit admission that the method no longer works on updated systems. This article explains what happened, how KMS38 worked, why Microsoft’s fix is reasonable from a security and operational standpoint, what risks remain, and practical remediation and auditing steps for home users, system administrators, and imaging teams.

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Background: how KMS activation and KMS38 worked​

What is KMS?​

KMS (Key Management Service) is Microsoft’s legitimate volume-activation solution designed for organizations. It issues activation leases that require periodic renewal (historically every 180 days) by contacting a KMS host on the network. KMS is intended for corporate licensing flows, not for consumer or single-device activations.

What made KMS38 attractive?​

KMS38 was a technique — implemented in community activators like MAS (also called MASSGRAVE) — that produced a crafted activation artifact (commonly described as a “GenuineTicket”) and leveraged Windows upgrade tooling to carry that ticket into the target system in a way that made the OS treat the machine as if it had an extended KMS activation period up to the Y2K38 timestamp boundary (January 19, 2038). The trick was appealing because:

• It could be performed offline.
• It left little persistent footprint on the system (no long-running service or easily detectable process).
• It did not require a contactable KMS server nor a visible license key entry on the client.

Because of those attributes, KMS38 became a favored tool for users seeking free, persistent activation without online validation. But its implementation relied on specific internal behaviors in Windows setup and the upgrade helpers — notably gatherosstate.exe and associated flows — making it brittle.

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What changed in November 2025 (the technical facts)​

Microsoft’s November 11, 2025 cumulative updates (combined in KB5068861 for Windows 11 and companion KBs for other SKUs) consolidated prior preview fixes and servicing changes, including adjustments to the upgrade and servicing stack and the behavior of migration helpers. Those changes affect:

• The presence and behavior of gatherosstate.exe and similar helper binaries used during upgrades and imaging.
• How upgrade flows read and accept “GenuineTicket”-style artifacts.
• The servicing stack and image manifests included in ISOs that in-place upgrades rely upon.

Microsoft documents that KB5068861 rolls in fixes and non-security preview content from prior updates; community research and MAS repository changes show this set of servicing changes removed the assumptions KMS38 relied on, causing the activation trick to stop working on updated systems. MAS maintainers responded by removing KMS38 from the current script channel and directing users to other methods (HWID, TSforge) — which themselves carry legal and security concerns. The MAS commit log shows the KMS38 option being deprecated or removed from active flows as project maintainers adapt to Microsoft’s hardening.

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Why Microsoft’s fix was inevitable — and why it matters​

• Software activation is a vendor-controlled surface: Activation is directly tied to product licensing and revenue models. When mechanisms intended for legitimate upgrade/repair flows are co-opted to manufacture indefinite activations, the vendor has both legal and operational reasons to close the loophole.
• Attack surface reduction: Any helper that processes activation metadata is attractive to miscreants. Closing unintended uses of that helper reduces the risk that malicious actors will use the same pathway to forge activation state or to hide persistent changes.
• Operational stability: Organizations and imaging teams rely on consistent servicing behavior. Fixing fragile behaviors that third parties exploit reduces unexpected activation changes following routine updates.
• It’s technically fragile: KMS38 had always been dependent on internal upgrade-time behavior (gatherosstate and similar). When vendors update the servicing stack or installation media, hacks that rely on those details break — and that’s what happened here.

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What this means for different audiences​

Home users​

• If you used KMS38 (via MAS or another activator), installing the November 2025 cumulative updates may revert your PC to an unactivated state. You will see the “Activate Windows” watermark and personalization restrictions, and you’ll have to provide a legitimate key to restore activation.
• Continuing to use or re-run unauthorized activation tools carries malware and supply-chain risks. A trojanized copy of a popular activator is an easy way for attackers to reach millions. Past history shows these tools are frequently repackaged with malicious code. Treat free activation scripts as a high-risk approach to system health.

IT administrators and imaging teams​

• Any image, ISO, or offline deployment process that relied on carry-across activation artifacts must be audited immediately. Installation media created prior to the November updates may still behave differently from media that contains updated servicing binaries. Validate your imaging pipeline and test feature updates or repairs in lab conditions before broad rollouts.
• For businesses, using unauthorized activators is a compliance and legal risk. Audits or procurement reviews could expose organizations to penalties and remedial costs.

Security teams​

• Evaluate endpoints deployed with questionable activation methods as potential compromise vectors. These systems have already permitted third-party code with elevated privileges to run — a red flag for supply-chain or malware exposure. Investigate and consider full reimage and forensic validation where appropriate.

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The practical verification checklist (what to run now)​

• Check for the November 2025 cumulative update(s) on the device:
• Settings > Windows Update > Update history (confirm whether KB5068861 and related November packages are installed).
• Confirm activation state:
• Settings > System > Activation or run: slmgr.vbs /xpr
• If activation changed following the update, the device likely relied on one of the now-broken ticket-carry flows.
• Audit installed tools and scripts:
• Look at scheduled tasks, installed programs, and last-modified files in system paths. Watch for downloads or execution entries that correlate with activator scripts.
• For imaging: rebuild your installation media from official Microsoft ISOs and test upgrades and repairs against the latest servicing stack (SSU + LCU). Microsoft’s KB pages include file manifests you can use to verify included binaries.
• Decide remediation:
• Purchase or assign legitimate licenses where required.
• If windows will remain unlicensed, accept the reduced functionality and consider migrating to legally supported alternatives (Windows 10 with Extended Security Updates where applicable, Linux distros, or ChromeOS Flex depending on workflow).
• Document and report:
• Record which devices used unauthorized activation and when updates were applied. This will be essential if you need to justify security remediations or licensing compliance actions.

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Risks, trade-offs, and the cat-and-mouse reality​

Security and supply-chain hazards​

Even if MAS or similar scripts appear “clean” in their source, the distribution vectors are risky. Malicious actors routinely copy high-profile tools, alter them, and upload trojanized versions to popular file-sharing sites. Past incidents include malware-laden variants of utilities that bypass Windows 11’s hardware checks. Running unofficial scripts that require administrative privileges is a non-trivial danger.

Legal and compliance exposure​

Using unauthorized activation methods violates Microsoft’s licensing terms and, for organizations, can trigger contractual non-compliance. If an audit reveals the use of such tools, it may lead to remedial licensing purchases, fines, or loss of support agreements.

Operational fragility​

Hacks that rely on internal installer behavior are brittle. Routine vendor updates can — and do — change those details. If your production or imaging pipeline relied on such a trick, it will break unpredictably and possibly at scale when cumulative updates roll out.

The inevitable workaround question​

Where there’s demand, community maintainers will look for new methods. MAS and similar projects have historically adapted by pivoting to other approaches (HWID, TSforge). But each new technique carries its own lifecycle: it will work until Microsoft finds and closes the next unintended behavior. This is a classic cat-and-mouse game — technically interesting to researchers, but operationally unacceptable for business environments and hazardous for individual users who prize security and stability.

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Strengths and weaknesses of Microsoft’s move — a balanced look​

Strengths​

• Security hardening: Closing upgrade-time ticket carry-over reduces an exploitable surface that third parties abused.
• Licensing integrity: It protects Microsoft’s licensing model and the broader software ecosystem that depends on predictable revenue for maintenance and security engineering.
• Operational consistency: Reduces the “mystery activation” cases IT admins see after upgrades; if a machine is unlicensed, it’s because of policy, not a brittle trick that will break next month.

Weaknesses and downsides​

• User frustration: Enthusiasts and hobbyists who used these scripts for convenience will be inconvenienced.
• Migration pressure: Machines that cannot be upgraded due to hardware requirements or cost may be pushed toward unsupported options, or away from Windows entirely.
• Collateral effects risk: There is a small risk legitimate upgrade/repair scenarios that relied on genuine migration flows could be affected — though Microsoft’s KBs and servicing guidance aim to minimize that for supported scenarios.

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Recommended actions for admins and enthusiasts (prioritized)​

• Audit your estate (immediate): Identify devices that used MAS or similar tools and confirm their activation and update status. Prioritize business-critical hosts for reimaging or remedial licensing.
• Reimage suspect endpoints (high priority): When a system had third-party, privileged activation scripts run, assume potential compromise and reimage from a known-good image.
• Move to compliant licensing (medium priority): If you manage fleets, work with procurement to obtain proper volume licensing or bring-your-own-license (BYOL) strategies that make activation reliable and supportable.
• Harden update and imaging pipelines (ongoing): Ensure media and ISOs are rebuilt from official sources after major servicing changes, and test feature upgrades in staging before mass rollouts.
• For hobbyists: consider legal alternatives — buy a retail license, use Windows 10 with correct support arrangements where possible, or evaluate free and modern Linux distributions that now provide excellent desktop experiences.

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What remained unverified and what to watch next​

• MAS maintainers’ exact timeline and phrasing around removing KMS38 can vary across mirrors and commits; while a commit shows KMS38 being removed or deprecated in the current release channel, community claims about the “permanent” removal should be treated cautiously unless accompanied by an explicit, signed maintainer announcement. The project’s changelog and repository history show a pivot, but single-line claims across forums may oversimplify the nuance.
• Microsoft may continue to refine servicing and upgrade helpers; administrators should track future cumulative updates and review official KB file manifests if they depend on any edge-case upgrade behavior for legitimate migration scenarios.

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Final thoughts: durable licensing beats brittle hacks​

KMS38’s demise should be read as a practical lesson for IT operators and enthusiasts alike. Hacks that exploit upgrade internals can be clever and sometimes reliable for a time, but they are inherently temporary. The moment vendors close the loophole, systems and organizations still using such shortcuts face disrupted operations, compliance headaches, and security risk.
The November 2025 updates and the MAS maintainers’ response illustrate the core truth: the only durable path to secure, stable, and auditable Windows activation is compliant licensing and disciplined image/update management. For IT teams, the cost of remediation after an audit or a mass update will almost always exceed the cost of buying compliant licenses and building robust, tested deployment pipelines.

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Quick reference: commands and pages to run now​

• Confirm update history: Settings > Windows Update > Update history (look for KB5068861 / consolidated November 2025 updates).
• Check activation: Settings > System > Activation; or run from an elevated prompt:
• slmgr.vbs /xpr
• slmgr.vbs /dlv
• For imaging teams: re-create ISOs from Microsoft’s official download server and apply the latest SSU + LCU in a test lab before production rollouts.

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This change is a win for system integrity and a reminder that shortcuts that depend on internal implementation details rarely survive sustained vendor maintenance. Organizations and users should take the moment to audit, remediate, and align activation practices with supported licensing to avoid harder consequences later.

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Source: Windows Central Finally fixed: Microsoft closes door on a popular Win 11 activation hack