For years, tech-savvy users found a way to activate Windows permanently without connecting to Microsoft’s servers. The method, known as KMS38, allows people to set their system license to last until 2038 using an offline activation trick. It appears that those days are over now. Recent Windows updates quietly disabled the loophole, ending one of the longest-standing activation “hacks.” After installing the latest patches, many users noticed that previously activated systems suddenly showed the dreaded “Not activated” status.
KMS38 relied on modifying internal Windows licensing files to simulate activation through a Key Management Service (KMS). It wasn’t an official feature, just a clever repurposing of legitimate enterprise licensing tools. For years, it managed to survive through new Windows builds and updates.
That changed with recent cumulative updates for Windows 10 and 11, which now verify activation more aggressively and block the workaround at the kernel level. Even offline activations no longer work as before, leaving only genuine keys and digital licenses as valid options.
Some in the tech community see this as Microsoft tightening its grip before the wider rollout of Windows 11’s AI-integrated updates and new NPU-driven PCs. Others note that it was just a question of when the KMS38 loophole would be closed. Either way, it’s the end of an era. The trick that kept Windows running “activated” for 14 years into the future is now history.