A new Microsoft emergency Windows update has been issued after users discovered that August’s security patches broke core system recovery tools. The faulty updates (KB5063875 and KB5063709) left many PCs unable to reset or recover, with no warning inside Windows that the process would fail. Microsoft confirmed the issue and rushed an out-of-band patch.

The company urges users on Windows 11 23H2/22H2 and Windows 10 to install the fix immediately. Windows 11 24H2 systems are not affected.

Microsoft emergency Windows update details

The repair arrives as KB5066189 for Windows 11 and KB5066188 for Windows 10. Both are cumulative, meaning users don’t need to install the faulty updates first.

Microsoft highlighted a few important notes:

• The patch requires a device restart.
• No new security fixes are included beyond August’s release.
• Organizations yet to apply the August updates should deploy the OOB patch instead.

The recovery bug raised major concerns

Reset and recovery tools are often the last resort for PC users. With the bug in place, attempts to reset a device, repair using Windows Update, or trigger RemoteWipe CSP could silently fail. Critics argued Microsoft should have pulled the updates earlier. Windows Latest called it a “critical issue” since users had no visible warning that recovery would not work.

Other problems with the August updates

The reset bug isn’t the only headache. Reports continue to surface of SSD corruption when writing large files under August builds. That follows Microsoft’s repeated struggles this year with patches causing fresh problems while fixing others.

Why the Microsoft emergency Windows update matters

Trust in Windows updates has taken a hit. This Microsoft emergency Windows update underscores the stakes: when the tool meant to repair your PC doesn’t work, the fallout can be severe. For now, installing KB5066189 or KB5066188 is the only way to ensure recovery features function properly.