If a managed Windows PC loses automatic access to work or school networks, contact IT before changing security settings or buying hardware. A documented sign-in change may be responsible.
A security change, not a blanket Wi-Fi failure
Microsoft’s October 13 security update tightened an older way of signing in automatically to networks. Some work and school Wi-Fi, wired connections and virtual private networks—a secure connection to an organization’s systems—can be affected. This is not evidence that every Windows computer or ordinary home Wi-Fi network is broken.
The change targets NTLMv1-derived credentials, older sign-in information used by some MS-CHAPv2 network configurations. Microsoft says the new default applies when its Credential Guard protection is disabled and the relevant administrator setting has not already been configured. Its documentation covers Windows 11 version 24H2 and later, plus Windows Server 2025.
A university explains the real-world difference
York University’s October 16 advisory gives a concrete example: its IT team warned that affected Windows computers could lose access to AirYorkPLUS wireless. The university said it had adjusted a central policy as a workaround, while computers using its modern certificate-based sign-in through Intune were not affected.
That distinction matters more than the Wi-Fi brand on the box. Two computers in the same building can use different authentication arrangements. York’s response describes its own managed network, not a fix readers should copy onto another organization’s equipment.
What to do before replacing anything
Our advice is to tell your IT support team when the failure began, whether it affects wireless, wired or VPN access, and what error appears. Avoid uninstalling security updates or following an unfamiliar registry-editing tutorial simply to make the connection work.
Microsoft documents a temporary exception, but warns it weakens the new protection. Let administrators assess that trade-off and migration options. This explains one possible cause, not a diagnosis of every connection problem; an unrelated outage or hardware fault still needs its own investigation.
Sources & research
Source-based explainer of an October 13 change, not a new outage alert or hands-on diagnosis. Microsoft supplies the technical policy; York University supplies a separate account of its own network response. Checked October 24, 2026.