Latest Windows update is borking storage drives for some users

If there’s anyone you can trust to keep your copy of Windows up and running, it should be Microsoft, right? That’s true… until it isn’t. Some recent updates are causing severe stability issues for Windows 11, and the latest one might just make your solid-state drive (SSD) or hard drive (HDD) unreadable, though thankfully it seems to be an isolated issue.

According to Japanese user Necoru_cat on Twitter/X, the Microsoft Defender update issued last week for Windows 11 and Windows 10 introduced a new bug that’s causing some storage drives to be inaccessible. That includes drives that are hosting Windows itself, effectively borking the entire PC. Neowin reports that it’s an issue specifically for the latest 24H2 versions of Windows 11 (KB5063878, KB5063875) and Windows 10 (KB5063709, KB5063877, KB5063871, KB5063889).

Several other users are having the same issue, worried that their storage drives are broken. Neowin thinks that it might be a problem with some drives that have a specific NAND controller from supplier Phison, showing a mix of issues, some of which can be fixed automatically with a reboot and some of which can’t.

Reportedly, this bug is being triggered by heavy write sessions to NVMe SSDs and hard drives, possibly resulting in file corruption. Rebooting might help, but the problem seems to be persistent in the small amount of users it’s affecting, apparently only showing up when writing or backing up 50 gigabytes or more. Unfortunately it hasn’t been narrowed down to a specific range of drive models affected, and which might be saved by a firmware update. A similar issue was resolved in that way last year.