Microsoft has issued a formal response to user concerns that the August 2025 Windows 11 security update, KB5063878, may be responsible for rendering SSDs invisible. Reports circulated on social media claiming that after installing the update, drives were either no longer recognized in File Explorer and BIOS or had their partitions labeled as “RAW.” The implication was that the patch could be corrupting file systems or otherwise preventing proper access to solid-state storage.
In a service alert highlighted by BleepingComputer, Microsoft said it has conducted a full review and found no evidence linking KB5063878 to the SSD issues described. The company stated that it could not reproduce the behavior on internal systems, nor did its telemetry data suggest any spike in hardware failures or corrupted storage volumes following the update’s rollout. Microsoft emphasized that it continues to collect detailed reports from affected users in order to investigate further.
To reinforce its position, Microsoft has been working alongside major hardware partners to replicate the reported failures. Notably, NAND controller manufacturer Phison participated in the effort, running more than 4,500 hours of tests, but like Microsoft, was unable to identify any connection between the patch and SSD malfunctions. Despite this, both Microsoft and its partners say they are maintaining a cautious stance and will continue monitoring the situation.
In the meantime, Microsoft has issued a practical precaution: users whose SSDs are filled beyond 60 percent should avoid performing large-scale file transfers, such as moving or copying dozens of gigabytes at once. This advisory is not confirmation of a software flaw, but rather a safeguard while further investigations continue into what may be an unrelated storage failure pattern.
