Windows 11 January 2026 updates may cause boot failures on some PCs. Microsoft is investigating issues linked to KB5074109.

Wondering why your Windows 11 desktop keeps vanishing? It's because of this nasty bug.

Windows 11 KB5074109 (January 2026 Update) is causing major issues on some PCs, and Microsoft has more details to share.

A fresh wave of Windows 11 update trouble is making the rounds, and this one is about as disruptive as it gets: some PCs reportedly can’t boot after installing the latest January 2026 security update.

While the Windows world focuses on failed updates and a new automated upgrade that has just gone live for all users, Microsoft has also just issued a new Windows 11 update it describes as “critical.” ...

Microsoft has released a second emergency Windows 11 update, KB5078127, to fix Outlook crashes, cloud file errors, and other ...