KB5121003 deletes the Windows Hello PIN key at every reboot on Windows 11 (August 18, 2026)
Chapters
TL;DR
On Windows 11, the August update KB5121003 is leaving some PCs with a Windows Hello PIN that has to be enrolled again at every reboot, according to PCWorld on August 18, 2026. The stored sign-in key is deleted and recreated with a different key GUID at each start, and it is corrupt again by the next one. There is no fix as of August 18, 2026 and no Microsoft known issue, so the choice is re-enrolling every time or uninstalling the update.
- PIN sign-in fails at every reboot on affected PCs, and the user has to reconnect the Microsoft account and enroll a new PIN.
- Reports describe the credential key being deleted and recreated with a different GUID each boot, and the Windows Hello container failing to load.
- The builds are 26200.9168 on Windows 11 25H2 and 26100.9168 on 24H2, both from KB5121003 of August 11, 2026.
- It is described as isolated rather than widespread, but on an affected PC it breaks sign-in completely.
- Uninstalling KB5121003 is the only alternative to re-enrolling, and it gives up fixes for more than 400 vulnerabilities including an actively exploited zero-day.
What the sign-in failure looks like
The symptom is not a PIN that is occasionally refused. It is a PIN that is gone every time the machine starts. PCWorld lists Windows Hello PIN login errors with stored sign-in keys deleted or corrupted among the faults attached to the August update, in a piece by PC-WELT staff writer Laura Pippig.
For the person at the keyboard the loop is the same each morning: the PIN does not work, Windows asks for the Microsoft account instead, and the PIN has to be set up again. That gets you to the desktop. It does not survive the next restart.
Windows Hello is not an optional convenience on a machine set up around it. On a laptop with no other configured sign-in habit, a PIN that resets daily is the difference between opening the lid and starting a recovery exercise.
What the key GUID detail tells us
The most specific account comes from Windows Latest on August 16, 2026, which reports a user describing Windows deleting and recreating the key at each reboot with a different key GUID every time. So this is not a stored credential that has become unreadable and sits there failing. It is a new key each boot, and the new one is broken again by the following start.
Notebookcheck on August 17, 2026 lists the same set from the other direction: a PIN requiring re-enrollment after each reboot, credential key corruption during regeneration, and the Hello container failing to load.
Read together, those point at the regeneration step rather than at the stored credential. Something is recreating the key and producing one that does not survive. That is as far as the published evidence goes: no component has been named, and no error code has been published.
| Detail | Value as of August 18, 2026 |
|---|---|
| Symptom | PIN sign-in fails at every reboot, re-enrollment required |
| Underlying behaviour reported | Credential key deleted and recreated with a new GUID each boot |
| Also reported | Windows Hello container fails to load |
| Originating update | KB5121003, August 11, 2026 |
| Builds | 26200.9168 (25H2), 26100.9168 (24H2) |
| Microsoft known issue | None |
| Fix | None published |
How many people this hits
The reports describe this as isolated rather than widespread, and I have no figure to offer beyond that word. No affected-device list, no percentage, no pattern by hardware vendor or by account type has been published.
Isolated is not the same as unimportant. A crash that costs you a game is a nuisance; a sign-in method that resets daily makes a machine hostile to use. The narrowness matters only for one practical purpose: if your PIN still works on build 26200.9168 or 26100.9168, there is nothing here for you to act on.
The two options, and what each costs
Option one is to live with it: sign in with the account password, re-enroll the PIN when you need it, and keep the August patches. The cost is the daily loop and having your account credentials to hand every time the machine restarts.
Option two is to uninstall KB5121003. PCWorld flags that as not recommended, because the update removes critical security patches when it goes, and puts the update's coverage at more than 400 vulnerabilities. Notebookcheck calls the uninstall a last resort for the same reason: the update closes an actively exploited zero-day.
There is no third option on August 18, 2026. No registry change, no repair command and no Microsoft guidance has been published for this fault, and the driver removal that helps the game crashes in the same update has not been reported to change the Hello behaviour.
What you can do today
If your PIN is resetting on every restart, the order below keeps you working without giving up the August fixes:
1. Sign in with your account password. On the lock screen choose Sign-in options and pick the password instead of the PIN.
2. Make sure you can actually do that before you need to. Check that you know the Microsoft account password on the PC and that your account recovery details are current, because the reported loop involves reconnecting the account.
3. Confirm the build. Press Windows and R, type winver and press Enter. Expect 26200.9168 on 25H2 or 26100.9168 on 24H2.
4. Re-enroll the PIN only if you want it back for this session, and expect it to be gone after the next restart.
5. Treat an uninstall of KB5121003 as the last step, from Settings, then Windows Update, then Update history, then Uninstall updates. It returns a working PIN and removes fixes for more than 400 vulnerabilities, including one that is being exploited.
6. Do not delete inpoutx64.sys hoping it helps here. That driver belongs to the game crashes from the same update, not to Hello.
7. If you would rather not run this sequence yourself: Get XLAnt.
Frequently asked questions
Will removing and re-adding the PIN fix it permanently?
Not on the reports published as of August 18, 2026. The key is recreated at each boot with a new GUID and is corrupt again by the next start, so a fresh enrollment lasts for that session.
Has Microsoft acknowledged the Windows Hello failures?
There is no Microsoft known-issue entry for them as of August 18, 2026. The accounts come from users, reported by PCWorld, Notebookcheck and Windows Latest.