Windows 10 update broke DHCP, knocked users off the Internet

Microsoft has quietly fixed a software update it released last week, which effectively prevented Windows 10 users from connecting to the Internet or joining a local network.

It's unclear exactly which automatic update caused the problem or exactly when it was released—current (unconfirmed) signs point to KB3201845 released on December 9—but whatever it was appeared to break DHCP (Dynamic Host Configuration Protocol), preventing Windows 10 from automatically acquiring an IP address from the network.

There's also little detail on how many people were affected or why, but multiple cases have been confirmed across Europe by many ISPs. A Microsoft spokesperson has meanwhile confirmed that "some customers" had been experiencing "difficulties" getting online, but that's about it for public statements at present.

However, a moderator on the company's forums has said the fix was included in a patch released on Tuesday called KB3206632. The patch notes include the following line, which seems to indicate a fix:

Addressed a service crash in CDPSVC [Connected Devices Platform Service] that in some situations could lead to the machine not being able to acquire an IP address.

According to a statement from Virgin Media, the issue affects "anyone who wants to access the Internet from a computer with the downloaded Windows 10 software update, regardless of the ISP."

In the time-honoured tradition of IT support, Microsoft's advice begins by telling people to try turning their PCs on and off again:

To receive the update, customers may need to first restart their PCs by selecting Start on the taskbar, clicking the power button, and choosing "restart" (not "shut down"). Additional guidance can be found on our support forum here."

Slightly more comprehensive advice with other possible fixes is also available here.

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