KMS38 no longer works to activate Windows: what has changed and why

Everyone knows it: KMS38 no longer works to activate Windows. The popular free solution has lost all effectiveness. following the November 2025 security update that the Microsoft OS receivedBut what changed? Why doesn't it work anymore? We'll tell you everything in detail.

KMS38 no longer works to activate Windows: What happened?

If you've made it this far, you're probably aware that KMS38 no longer works to activate Windows 10 and 11. The news spread like wildfire in technical forums and GitHub communities after Windows received its security patch in November 2025. The tool became completely ineffectiveand computers activated with it began to display the watermark “Windows is not activated”.

But what happened? To understand the reason for its obsolescence, it's helpful to first know what KMS38 did. You might be surprised to learn that KMS (Key Management Services) It is a legitimate Microsoft technology.It is designed to allow large organizations to activate hundreds or thousands of PCs within their local network without needing to contact Microsoft servers on each machine.

• The “trick” of tools like KMS38 was emulate a KMS server locally, That is, on your own PC.
• After, It injected a generic product key and an activation ticket which simulated an activation valid until the year 2038 (hence the “38”).
• To achieve all this, it was necessary modify system records and services to point to the emulated KMS server.
• He also had to create programs for reassemble the license every so often and thus maintain the illusion of permanent activation.

But what made KMS38 such a popular tool was its less aggressive methodology. For example, it didn't patch critical system files, such as sppsvc.exe or tokens.dat, which made it more stable and less detectable by antivirusThat's why it worked so well in Windows 10 and early versions of Windows 11, as well as for activating the Microsoft Office suite.

Microsoft closes the gap

Why does KMS38 no longer work to activate Windows? Because Microsoft closed the loophole that allowed users to simulate activation with this and other tools. KMS38 was the preferred method for those looking to avoid paying for licenses. It became widely available thanks to... project Massgrave (MAS), which offered auditable open-source scriptsBut everything changed in November 2025.

Was in November 2025 when Microsoft launched a Patch Tuesday which changed how Windows verifies activations. With this security update, the company has decided to take decisive action and neutralize any attempt at illegitimate activation. Basically, the changes that affected the operation of KMS38 and similar technologies were:

Removing legacy artifacts: KMS38 no longer works to activate Windows

This was perhaps the most devastating blow to "pirated" activations and the main reason why KMS38 no longer works to activate Windows. KMS38 depended on what were called... GenuineTicketwhich are small files capable of transferring activation information between installations and updates.

Thanks to these devices, the system treated the equipment as if it had an activation lease valid until 2038. But, with the November 2025 update, Microsoft removed support for these artifacts, and thus broke the foundation of the KMS activation method.

Changes in the Software Protection Platform (SPP)

Another blow to KMS38 was the changes Microsoft introduced to the Software Protection Platform (SPP). This is the core of Windows license verification, and It was modified so that it no longer accepts grace period extensions or validations coming from emulated KMS serversIn other words: any attempt to use scripts like those of Massgrave It is detected and reversed automatically.

Blocking fake servers

The final blow that rendered KMS38 ineffective for activating Windows was the blocking of fake servers. It's important to remember that KMS38 worked by emulating a KMS server to trick the system. But the aforementioned patch introduced the active detection of these “pirate” serversinvalidating any previous activation and displaying the hated watermarks again. Checkmate!

KMS38 no longer works to activate Windows: the underlying reason

That's right: KMS38 no longer works to activate Windows or Office, which means the loss of a key tool for avoiding license fees. But it's worth noting that this isn't an isolated incident: It's part of a broader strategy by MicrosoftThe company has been fighting against the use of its services outside of its established terms for years, and this has been one of its best blows.

But it's not the only one it's done recently. A few months ago, Microsoft disabled the possibility of Install Windows 11 with a local account offline. Now It is mandatory to configure the system with an online accountThis increases dependence on other ecosystem services, such as OneDrive or Microsoft 365.

Little by little, Microsoft wants to regain full control over user licenses and minimize pirated accounts. The goal is to ensure that every active copy of Windows is linked to a legitimate key or digital account. Of course, Microsoft justifies the blocks by claiming that alternative activators could introduce malware. Sure, KMS38 was considered safe because of its open source code, but that didn't stop Microsoft from decommissioning it..

So what now?

Since KMS38 no longer works to activate Windows, only a few secure alternatives remain. With the definitive blocking of this activation method, it's time to... reconsider the advantages of using official licenses or accept the limitations of an unactivated system.

On the other hand, from Massgrave They propose the use of HWID (Hardware ID) or Tsforge activation methodsand are optimistic about the idea of ​​circumventing the KMS blockade in the future.

Meanwhile, Microsoft remains determined to close any backdoors, present and future. It has more than enough reasons to want to reinforce its business model based on legitimate licenses. For users, the decision is clear: adapt to the new rules or live with the restrictions.