Why Does Windows Lose Activation After a Feature Update? Here's the Fix!

Hi, it's me, Shiichan! Today I've got a story that's a bit dry but important if you manage Windows machines.

What was announced?

JP Windows Support, a blog run by Microsoft staff, published an article explaining a phenomenon where OS activation drops after installing a Feature Update, along with how to fix it. It was written by someone on the Windows Platform Support team who pulled together a pattern they see a lot in support cases.

Why does activation break?

The root cause: when a Feature Update is applied, the machine's specific product key gets wiped and replaced with a default one, leaving the OS unactivated. This tends to happen specifically in environments where a digital license was never granted in the first place.

Cases where a digital license doesn't get granted include:

• Firewalls or proxies block the licensing activation endpoints (restricted network environments)
• Activation is done via Web activation or VAMT (Volume Activation Management Tool)
• The Microsoft Account Sign-in Assistant service (wlidsv) is disabled

What changes

Now that the cause and the fix are documented, admins should be less likely to panic when activation suddenly looks broken after a Feature Update. Checking the digital license status beforehand means you can head off the problem before you even roll out the update.

Three main fixes are recommended:

• Get a digital license in place before applying the Feature Update (proactive)
• Re-run activation after the update (reactive)
• Switch to a different activation method (away from Web activation or VAMT)

Dive Deep

To check whether a digital license has been granted, go to Settings → System → Activation and look for "Windows is activated with a digital license." There's no way to check this via a command or the registry — it has to be confirmed visually on that screen.

Re-activating requires an internet connection, and if your network is restricted, you'll need to allowlist endpoints such as https://licensing.mp.microsoft.com/. In environments where the wlidsv service is disabled, you'll need to enable it first before retrying activation.

Wrap-up

• Activation dropping after a Feature Update happens because the machine's specific product key gets replaced with a default one.
• Restricted networks, Web activation/VAMT usage, and a disabled wlidsv service are common reasons a digital license was never granted.
• The only way to confirm digital license status is to check Settings → System → Activation visually.
• Fixes: get a digital license beforehand, re-activate afterward, or switch activation methods.
• Especially worth reading for IT admins who roll out Windows Feature Updates across an organization.