Microsoft has finally responded to the rumors and grumblings that accuse Windows 11 update KB5063878 of cutting off access to SSDs. Under certain circumstances, Windows will no longer display an existing SSD—or simply displays the partition as “RAW.” This disappearance affects the existence of an SSD in both File Explorer and the BIOS.
Microsoft said in a service alert (spotted by BleepingComputer) that it found no connection between the problems described by some users and Windows 11 update KB5063878, and that it couldn’t reproduce the problem on current systems. The company then began collecting user reports with additional details from those affected.
“After thorough investigation, Microsoft has found no connection between the August 2025 Windows security update and the types of hard drive failures reported on social media,” Microsoft said. “As always, we continue to monitor feedback after the release of every Windows update, and will investigate any future reports.”
Microsoft has been working with storage device partners to reproduce the problem, but noted that neither telemetry data nor internal testing has shown an increase in hard drive failures or file corruptions after installing the August 2025 Windows 11 24H2 security update.
Among others, NAND controller manufacturer Phison worked with Microsoft to fix the problem, but was also unable to find a cause for the reported errors after completing their 4,500-hour investigation.
Until the root cause is found and fixed, Windows 11 users with hard drives that are more than 60 percent full are advised to avoid downloading, copying, or writing large files (i.e., several dozen GB in size).
This article originally appeared on our sister publication PC-WELT and was translated and localized from German.