UPDATE: Since this story was published Microsoft has issued a fix for this issue.
Microsoft is investigating reports that a recent Windows update is stopping some PCs from connecting to the internet.
A patch pushed out by Microsoft last week seems to have left some Windows 10 and 8 machines unable to get online, as a result of PCs not being able to request a local IP address from routers.
In the UK, customers of major ISPs PlusNet and Virgin Media are complaining about not being able to get online following the update.
"Some customers have reported difficulties connecting to the internet," a Microsoft spokesperson acknowledged. A Microsoft staff member said the firm is looking into the reports and recommended that those affected restart their PCs. If that doesn't work, the Microsoft employee suggests visiting Microsoft's network support page.
Virgin Media blamed the problems on the "latest update" to Windows 10, and also provided instructions for resetting Windows' network stack, which it says may fix the problem.
PlusNet also pointed to a Windows update as causing the issue, which it says is preventing PCs from getting Dynamic Host Configuration Protocol (DHCP) information from routers, a necessary step when assigning a local IP address to a device. PlusNet recommends those affected follow this guide, which will walk them through setting up their PC with a static IP address.
The exact update that caused these problems is unclear, but it is not the first time that Windows patches have caused issues for users. Earlier this year the Windows 10 Anniversary Update triggered complaints about frozen systems and broken webcams among Home users.
Unlike most other editions of Windows 10, the Home edition can't defer receiving updates for several months, in order to wait for any early issues to be ironed out.
A group of Windows 10 Home users have previously petitioned Microsoft to allow them to delay when updates are applied.
Read more on Windows 10 and updates
Nick Heath is chief reporter for TechRepublic. He writes about the technology that IT decision makers need to know about, and the latest happenings in the European tech scene.