Microsoft has pulled the preview of an update for Windows 11 ahead of next week's cumulative batch after it sparked "blue screen of death" crashes for users.
Microsoft issues security updates on the second Tuesday of every month, colloquially known as Patch Tuesday; alongside that, Microsoft often issues non-security updates to save admins on restarts.
The troubled update that was distributed was a non-security preview for next week's October Cumulative Update, meaning it hasn't impacted as many people as if it went out as part of the wider Patch Tuesday package.
In this preview, Microsoft released an update to Windows 11 service stack (KB5043143), the component that installs Windows updates itself.
Microsoft said in a statement on its support pages: "Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates."
The company admitted there were known issues in the update, including crashing computers. "After installing this update, some customers have reported that their device restarts multiple times or becomes unresponsive with blue or green screens," the company said in its support pages.
"According to the reports, some devices automatically open the Automatic Repair tool after repeated restart attempts," the company added, referencing a system that attempts to diagnose and repair issues. "In some cases, BitLocker recovery can also be triggered."
Beyond trapping uses in a cycle of blue screens and reboots, the problematic update is also wreaking havoc with hardware that's connected via USB or Bluetooth, such as keyboards, mice, printers and so on. After the update, some no longer work and the USB Host Controller under Device Manager shows a yellow exclamation mark.
Microsoft is addressing the Windows update problem
Microsoft is addressing the issue itself via a Known Issue Rollback (KIR), which is a system introduced to reset computers to a previous state following a problematic update.
Managed devices, such as those in enterprises, can immediately resolve the issue by installing and configuring a policy detailed in Microsoft's support pages.
"Please note that it might take up to 24 hours for the resolution to propagate automatically to consumer devices and non-managed business devices and business devices that are not managed by IT departments," the company added. "Restarting your Windows device might help the resolution apply to your device faster."
The flawed update has been pulled so can no longer be downloaded or installed. Microsoft said it is continuing to investigate the issue, and it remains unclear at the time of writing whether the service stack features will be part of next week's cumulative update.
Problems with Microsoft updates aren't uncommon, and in this instance the blue screen issue was in a preview, rather than an update rolled out to all Windows 11 users — that highlights the importance of these testing programmes.
Earlier this year, a flawed update from CrowdStrike caused widespread disruption, while reports this summer revealed a Patch Tuesday update caused disconnections for Windows Server users.
