When users install monthly updates for Windows, particularly during the well-known Patch Tuesday releases, a single reboot is typically expected. However, recent observations suggest a shift in this pattern, with devices occasionally rebooting twice to complete the installation of substantial updates, such as the July 2026 Update.
Upon installing the April 2026 Update, I experienced a double reboot on my PC. Inquiries directed to Microsoft revealed that this behavior could be linked to Secure Boot, although it is not the sole factor at play. A similar occurrence was noted with the July 2026 Update (KB5101650) on a system where the Secure Boot certificate update had already been implemented. This time, the cause was attributed to the .NET Framework update.
Why Windows Update is rebooting some PCs twice
Windows 11 may initiate a reboot to install the monthly Patch Tuesday update, followed by an additional reboot to finalize the installation of a separate .NET Framework or Secure Boot update. It is important to note that this does not imply that Windows 11 devices will experience multiple reboots for updates every month. Such occurrences may happen once or twice a year, or potentially more frequently if various versions of the .NET Framework are installed, and if the Secure Boot certificate update is hindered by compatibility issues.
In any case, whether the multiple reboots stem from a pending Secure Boot update or a significant Windows update that encompasses both Patch Tuesday and .NET Framework updates, users are advised to remain calm. It is best not to panic or press the power button during these reboots; instead, allow the system ample time to complete the installation process, which may take longer than ten minutes.
The .NET Framework update may require a separate reboot
According to Windows Latest, the July 2026 .NET Framework update, if applicable to your device, may necessitate a distinct reboot. While not all .NET Framework updates require this additional reboot, the July 2026 Update is one such instance. If your PC has already received the Secure Boot certificate update, it is likely that the .NET Framework update is the reason for the double reboot this month.
Microsoft is still rolling out the Secure Boot certificate update
In certain scenarios, Windows Update may trigger multiple reboots to apply the Secure Boot 2023 certificate update. Although Microsoft previously indicated that the deployment of these updated certificates would be completed by June 2026, recent communications suggest that the rollout is still in progress. The company reassured users that PCs lacking the required Secure Boot 2023 update will continue to function normally, alleviating concerns about potential disruptions.
“Microsoft has been updating these certificates on PCs and non-managed business devices for the past months,” the company stated in an updated communication. “Devices that haven’t received the newer certificates will continue to start, and standard Windows updates will continue to install. We will continue to install the newer certificates via Windows updates in the coming months.”
It is also crucial to heed Microsoft’s warning against delaying updates for more than three days, as the size of these updates is expected to increase in response to AI-assisted vulnerability detection identifying more security flaws. Microsoft has reported that over 570 significant security issues have been addressed in Windows.
For the time being, users may need to accommodate multiple reboots. It is somewhat ironic that Microsoft has pledged to minimize reboots to just one per month, yet current experiences reflect the opposite. The anticipated changes aimed at reducing reboots have not yet been implemented, but once they are, users can expect Windows to reboot no more than once a month unless they opt for one of the optional preview updates.
Event Viewer began logging SCEP certificate errors after installing the July 2026 Windows update
Some users may notice that the Event Viewer is logging SCEP certificate-related errors following the installation of the July 2026 Update. If you find yourself in this situation, it may be worthwhile to check the Event Viewer for a log specifically detailing SCEP certificate failures:
Registration of the SCEP certificate for the Local System element via the endpoint https://AMD-KeyId-4b7b776d35db9c32bddb98b4dded844a38a66acd.microsoftaik.azure.net/templates/Aik/scep has failed: SubmitDone Submit(Request): Too Many Requests HTTP/1.1 429 Too Many Requests Date: Wed, 15 Jul 2026 09:38:31 GMT Content-Length: 17 Content-Type: text/HTML Retry-After: 20 client-request-id: fd1a778f-46cd-4701-84e1-e73a4a3ece83 Method: POST (860ms) Stage: SubmitDone Error 0x801901ad (-2145844819)
The AIK, or Attestation Identity Key, is linked to the PC’s Trusted Platform Module and serves as a means for Windows to verify the device’s trustworthiness. Windows requests the certificate through SCEP, which stands for Simple Certificate Enrollment Protocol. In this instance, error code 0x801901ad indicates an HTTP 429 error, signifying that too many requests were made.
It is possible that the July 2026 update has prompted some Windows installations to renew, validate, or request TPM attestation certificates again after installation or during a subsequent startup. Users need not be concerned about this error, as the Windows update will ultimately apply the necessary certificate changes in due course.
