Windows 7 PCs are being force fed a diet of Windows 10, breaking a promise made by Microsoft.
The problem is affecting domain-attached Windows 7 PCs not signed up to Windows Server Update Services (WSUS) for patches and updates, but looking for a Microsoft update instead.
The upshot is PCs, ranging from 10s to hundreds at a time, simultaneously chowing down on the 3GB-plus Windows 10 load, killing business networks.
The problem began showing up on Monday with complaints beginning to notch up online.
One Reg reader got in touch to complain: “Customers using hosted services are really struggling with the competition for bandwidth – effectively taking them off the air.”
And it’s all happening despite Microsoft promising – here – that it wouldn’t.
According to that advice, the Windows 10 upgrade is automatically blocked when the computer or device is joined to a domain. It's one of the firm's three scenarios when the update is blocked.
Users have logged urgent enquiries with Microsoft’s helpdesk but in the meantime have resorted to triage to stop the problem.
That means blocking traffic at the firewall stage that would normally have gone to Microsoft Update. Another option is to switch settings to the WSUS server.
The Reg contacted Microsoft for comment. We will update you with their response. ®